2. The Internet and the World Wide Web3. Application Software4. System Software5. Hardware: The CPU and Storage
- 1. Introduction to Information Technology
- 6. Hardware: Input and Output
- 7. Networks and Communications
- 8. Files, Databases, and E-Commerce
- 9. The Challenges of the Digital Age
- 10. The Promises of the Digital Age
- 11. Information Systems
1. Introduction to Information Technology
- Infotech Is Commonplace. Information technology (IT) is a general term that describes any technology that helps to produce, manipulate, store, communicate and/or disseminate information. IT merges computers with high-speed communications links. Two important parts of information technology comprise computers and communications. Computer is a programmable, multi use machine that processes data into information. Communications technology consists of electromagnetic devices and systems for communicating over distances. Online meansusing a computer or other device to access information and services via a network.
Infotech has given us some now-commonplace technologies: Email refers to messages transmitted over a computer network, a communications system connecting computers. There are guidelines governing the use of emails, which internet users should be aware of, to avoid viruses and other hazards. Major components of cyberspace —the wired and wireless world of communications—are the internet, a network of hundreds of thousands of smaller networks, and its graphical subsection, the World Wide Web, which stores information in multimedia form—text, graphics, sound, video. Phones entering the market can plug into computer chip based sensing devices, and translate data for transmission. Devices include health monitors and automotive diagnostic devices.
- The "All-Purpose Machine." Computers are of five types from largest to smallest. (1) Supercomputers —perform 1 trillion calculations per second. These are the most expensive but fastest computers available. (2) Mainframes —for processing millions of calculations, often accessed by a terminal, a display screen, and keyboard, which cannot do its own processing. (3) Workstations —used for scientific, mathematical, engineering, and certain manufacturing applications. (4) Microcomputers —personal computers, which may be desktop PCs, tower PCs, laptops, or personal digital assistants (PDAs); frequently used to connect to a local area network (LAN), which links equipment in an office or a building. (5) Microcontrollers —tiny specialized computers installed in cars and appliances. Servers are central computers holding data and programs for many other computers.
- Understanding Your Computer: You should know three things: (1) The purpose of a computer is to process data (raw facts) into information (summarized data). (2) Hardware consists of machinery and equipment; software instructs the hardware what to do. (3) Computers perform four basic operations: input, putting data into the system; processing, manipulation of data into information; storage, of two types—memory, which temporarily holds data to be processed, and secondary storage, which holds data or information permanently; output, putting out the results of processing. In addition, communication could be considered a fifth operation.
Input hardware includes the keyboard, which converts characters into signals readable by the processor, and the mouse, used to manipulate objects on the display screen.Processing and memory hardware includes the case (system cabinet), which contains: a processor chip with miniature electronic circuits that process information in megahertz, millions of processing cycles per second; and memory chips (RAM chips),which temporarily hold data prior to processing. Both chips are mounted on the motherboard, which contains expansion slots for plugging in additional circuit boards. Secondary storage hardware includes: a floppy-disk drive, which stores data on removable 31?2-inch disks; a Zip-disk drive, which stores data on floppy-disk cartridges with at least 70-170 times the capacity of the standard floppy; a hard-disk drive, which stores data on a non removable disk platter that has much greater capacity than floppies; and a CD/DVD drive, which reads data from optical disks.Output hardware includes: a video card, which converts processor information so it can be displayed as text and images on the monitor; a sound card, which outputs sound to speakers; and a printer, which produces images and text on paper. Communications hardware includes a modem, which sends and receives data over phone lines to and from computers.Software is of two types. System software helps the computer perform essential operating tasks. Application software performs specific tasks for the user, such as word processing.
- Where is Infotech Headed? Computer developments have focused on three areas: miniaturization, speed, and affordability. Three developments in communications may be noted: connectivity, the ability to connect with computers via communications lines; interactivity, enabling a user to have a two-way dialogue; and multimedia. The melding of computers and communications has produced three developments: convergence, the combining of several industries through the language of computers; portability; and personalization. One result of these developments is information overload. Three ethical concerns raised by information technology are associated with speed and scale, unpredictability, and complexity.
Technology that merges computing with high-speed communications links carrying data, sound, and video. Why it's important: Information technology is bringing about the fusion of several important industries dealing with computers, telephones, televisions, and various handheld devices.
The Charles Babbage Institute Center for the History of Information Technology is an historical archives and research center located at the University of Minnesota. It offers a wealth of resources on the history of information technology, including a fascinating look at "Hollywood & Computers."
Programmable, multiuse machine that accepts data—raw facts and figures—and processes (manipulates) it into useful information, such as summaries and totals. Why it's important: Computers greatly speed up problem solving and other tasks, increasing users' productivity.
Electromagnetic devices and systems for communicating over long distances. Why it's important: Communications systems using electronic connections have helped to expand human communication beyond face-to-face meetings.
Using a computer or other information device, connected through a network, to access information and services from another computer or information device. Why it's important: Online communication is widely used by businesses, services, individuals, and educational institutions.
Knowledge in Action
Interview three of your acquaintances about the use of online communications. How do online communications help them perform tasks? How many hours do they spend online? Do they experience problems while performing tasks online? Write a short report summarizing the results of your interviews.
Messages transmitted over a computer network, most often the internet. Why it's important: Email has become universal; one of the first things new computer users learn is how to send and receive email.
Communications system connecting two or more computers. Why it's important: Networks allow users to share applications and data and to use email. The internet is the largest network.
Term used to refer to the online world and the internet in particular but also the whole wired and wireless world of communications in general. Why it's important: More and more human activities take place in cyberspace.
Knowledge in Action
Interview several of your friends and acquaintances to see how they participate in activities occurring in cyberspace. Do they communicate using email? Do they purchase items over the World Wide Web? Do they participate in online chat rooms? See if you can come up with at least ten different activities occurring in cyberspace. Write a paragraph or two summarizing your findings.
Worldwide network that connects hundreds of thousands of smaller networks. Why it's important: Thanks to the internet, millions of people around the world can share all types of information and services.
World Wide Web:
The part of the internet that stores information in multimedia form—sounds, photos, and video as well as text. Why it's important: The web is the most widely known part of the internet.
Multimedia refers to technology that presents information in more than one medium, including text graphics, animation, video, and sound. Why it's important: Multimedia is used increasingly in business, by professionals, and education to improve the way information is communicated.
High-capacity computer with hundreds of thousands of processors that can perform trillions of calculations per second. It is typically priced from $500,000 to more than $350 million. Why it's important: Supercomputers are used primarily for research purposes, airplane design, oil exploration, weather forecasting, and other activities that cannot be handled by mainframes and other less powerful machines.
Water- or air-cooled computers costing $5000–$5 million. Small mainframes are often called midsize computers. Why it's important: Mainframes are used by large organizations (banks, airlines, insurance companies, universities) that need to process millions of transactions.
Knowledge in Action
Your college or university undoubtedly uses one or more mainframes for its data-processing needs. Find out how many of these mainframes exist on your campus, what they are used for, and their manufacturer. Write a paragraph or two summarizing your findings.
Input and output device that uses a keyboard for input and a monitor for output; it cannot process data. Why it's important: Terminals are generally used to input data to and receive data from a mainframe computer system for example, in airline reservation systems.
Expensive, powerful computer generally used for complex scientific, mathematical, and engineering calculations and for computer-aided design and computer-aided manufacturing. Why it's important: The power of workstations is needed for specialized applications too large and complex to be handled by PCs.
Hewlett-Packard, IBM, and Sun Microsystems are three of the leading manufacturers of computer workstations.
Also called personal computer; small computer that fits next to a desk or on a desktop, or can be carried around. Costs $500–$5000. Why it's important: The microcomputer has lessened the reliance on mainframes and has provided more ordinary users with access to computers. It can be used as a stand-alone machine or connected to a network.
Microcomputer unit whose case sits on a desk with the keyboard in front and the monitor often on top. Desktop PCs and tower PCs are the most commonly used types of microcomputer.
Knowledge in Action
Take yourself on a walking tour of your college library. Create an inventory of all the computers available for student use in the library. Categorize each computer as one of the following: desktop, laptop, tower, or terminal (no processing capability). The last of these—terminal—may still be used for the electronic card catalog. Report your findings to your class.
Microcomputer unit whose case sits as a "tower" often on the floor, freeing up desk space.
Now more commonly called notebook computer, lightweight portable computer with a built-in monitor, keyboard, hard-disk drive, battery, and adapter; weighs 1.8–9 pounds. Why it's important: Laptops and other small computers have provided users with computing capabilities in the field and on the road.
Personal Digital Assistant (PDA):
Also known as handheld computer or palmtop; used as a schedule planner and address book and to prepare to-do lists and send email and faxes. Why it's important: PDAs make it easier for people to do business and communicate while traveling.
Local Area Network (LAN):
Network that connects, usually by special cable, a group of desktop PCs and other devices, such as printers, in an office or building. Why it's important: LANs have replaced mainframes for many functions and are considerably less expensive.
Also called an embedded computer; the smallest category of computer. Why it's important: Microcontrollers are built into "smart" electronic devices, such as appliances and automobiles.
Computer in a network that holds collections of data (databases) and programs for connecting PCs, workstations, and other devices, which are called clients.Why it's important: Servers enable many users to share equipment, programs, and data.
Raw facts and figures that are processed into information. Why it's important: Users need data to create useful information.
Use the web to learn more about the plethora of careers involving data. Go to a site such as www.hotjobs.com and type "data" into the Search field. How many jobs matched the keyword? Which ones sound most interesting to you? Why? Write a paragraph summarizing your findings.
Data that has been summarized or otherwise manipulated for use in decision making. Why it's important: The whole purpose of a computer (and communications) system is to produce (and transmit) usable information.
All machinery and equipment in a computer system. Why it's important: Hardware runs under the control of software and is useless without it. However, hardware contains the circuitry that allows processing.
The Institute of Electrical and Electronics Engineers (IEEE) is an association of technical professionals in fields such as computer engineering, biomedical technology, consumer electronics, and aerospace. It has over 350,000 members from 150 different countries. The website for www.IEEE.org contains a large amount of information concerning careers involving hardware.
Also called programs; step-by-step electronic instructions that tell the computer hardware how to perform a task. Why it's important: Without software, hardware is useless.
The Association for Computing Machinery (ACM) is the world's first educational and scientific computing society. Founded in 1947, the ACM now has over 80,000 members—both computing professionals and students. The ACM maintains a Career Resource Center on its website, which is an invaluable source of information about careers in the software field.
Whatever is put in ("input") to a computer system. Input devices include the keyboard and the mouse. Why it's important: Useful information cannot be produced without input data.
Knowledge in Action
Visit your college's student computer lab. Make a list of all the different kinds of input devices available for students to use. Is there any missing which you think should be provided?
The manipulation the computer does to transform data into information. Why it's important: Processing is the essence of the computer, and the processor is the computer's "brain."
CareerJournal.com is a career site sponsored by the Wall Street Journal. Visit this site to search for jobs in "data processing," another term often used interchangeably with "processing."
Part of the computer in which data and programs are stored, either permanently or temporarily.
To learn about the data storage industry, visit the website for the industry's trade association - IDEMA.
Also called primary storage RAM; computer circuitry that temporarily holds data waiting to be processed. Why it's important: By holding data, memory enables the processor to process.
Knowledge in Action
Determine how much memory is installed in the computer you use.
Devices and media that store data and programs permanently—such as disk drives, tape drives, and CDs and DVD drives. Why it's important: Without secondary storage, users would not be able to save their work. Storage also holds the computer's software.
Knowledge in Action
Determine how much secondary storage exists in all the secondary storage devices of the computer you use.
Whatever is output from ("put out of") the computer system; the results of processing. Why it's important: People use output to help them make decisions. Without output devices, computer users would not be able to view or use the results of processing.
Knowledge in Action
Visit your college's student computer lab. Make a list of all the different kinds of output devices available for students to use. Is there any missing that you think should be provided?
Input device that converts letters, numbers, and other characters into electrical signals readable by the processor. Why it's important: Keyboards are the most common kind of input device.
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Most keyboards were designed with a right-handed computer user in mind. However, approximately 10% of the population is left-handed. Some manufacturers produce keyboards especially for the left-handed computer user. One website that offers such keyboards for sale is thelefthand.com. Note the differences in the left-hand keyboard pictured on their site. The numeric pad has been moved from its normal position on the right-hand side of the keyboard to the left-hand side. Similarly, the arrow keys along with the help, home, page up, page down, etc., keys that are normally adjacent to the numeric pad have been moved to the left-hand side of the keyboard. These two changes would allow a left-handed user to do frequent operations such as numeric data-entry and up/down, left/right movements on the screen with his or her dominant hand—the left one.
Input device used to manipulate objects viewed on the computer display screen. Why it's important: For many purposes, a mouse is easier to use than a keyboard for inputting commands. Also, the mouse is used extensively in many graphics programs.
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A computer mouse may provide one, two, or three buttons, depending on which system software it is to be used with. Most use two buttons since that is the number needed for working with the popular Microsoft Windows operating system.
Case (System Cabinet):
Also known as the system unit or system cabinet; the box that houses the processor chip (CPU), the memory chips, and the motherboard with power supply, as well as storage devices—floppy-disk drive, hard-disk drive, and CD or DVD drive. Why it's important: The case protects many important processing and storage components.
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The popular iMac microcomputer manufactured by Apple Computer does not have a case separate from its monitor. Instead, the monitor, CPU, memory chips, motherboard, power supply, hard-disk drive, and CD or DVD drive are all contained in one compact unit.
Tiny piece of silicon that contains millions of miniature electronic circuits used to process data. Why it's important: Chips have made possible the development of small computers.
Fred Terman is considered the "father" of Silicon Valley—that part of California stretching from San Jose to San Francisco, and that features a high concentration of high-technology companies. Use the web to research the life of Fred Terman, focusing on why he has come to be associated so closely with Silicon Valley. Write a one-page biographical sketch of Terman and present it to your class.
Memory Chips (RAM Chips):
Random access memory; provides primary storage or temporary storage. Why it's important: Temporarily holds data before processing and information after processing, before it is sent along to an output or storage device.
Main circuit board in the computer. Why it's important: This is the big green circuit board to which everything else—such as the keyboard, mouse, and printer—is connected. The processor chip, memory chips, ROM chips, and other circuitry is mounted on the motherboard.
Knowledge in Action
Research the etymology (origins) of the word "motherboard." Are there other similar terms in use, such as "fatherboard," "daughterboard," and "sonboard?" When was the term "motherboard" first used? Is a particular individual credited with having coined the word? Write a short paragraph on your findings.
Internal "plugs" used to expand the PC's capabilities. Why it's important: Expansion slots give you places to plug in additional circuit boards, such as those for video, sound, and communications (modem).
Storage device that stores data on removable 3.5-inch-diameter flexible diskettes encased in hard plastic. Why it's important: Floppy-disk drives are included on almost all microcomputers and make many types of files easily portable.
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In 1998, Apple Computer introduced a brand new microcomputer named the iMac. Its colorful plastic exterior was hailed as a major design innovation. More controversial was Apple's decision to not include a floppy-disk drive in the iMac. As a result, many iMac owners have resorted to purchasing external floppy-disk drives or making major modifications to permit an internal floppy-disk drive to be installed.
Storage device that stores data on removable floppy-disk cartridges with at least 70 - 170 times the capacity of the standard floppy. Why it's important: A Zip drive is a removable storage device that securely stores all the important computer data magnetically. They are durable, portable, easy-to-use, and extremely efficient. One Zip 250 MB disk can store the same amount of data as 173 floppy disks.
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In 1994 Iomega introduced its first Zip drive with its removable 100 MB cartridge-like disks.
Storage device that stores billions of characters of data on a non removable disk platter inside the computer case. Why it's important: Hard disks hold much more data than diskettes (floppies) do. Nearly all microcomputers use hard disks as their principal secondary-storage medium.
Knowledge in Action
Determine how much total hard-disk storage capacity your computer has. Explain the method in which to learn how much of that capacity is already in use.
Storage device that uses laser technology to read data from optical disks. Why it's important: New software is generally supplied on CDs rather than diskettes. And even if you can get a program on floppies, you'll find it easier to install a new program from one CD rather than repeatedly inserting and removing many diskettes. The newest version is called DVD (digital video disk). The DVD format stores even more data than the CD format.
Many people who have to travel often for work like to take along their notebook computers so that they can make good use of their time while flying in an airplane, waiting at airports, etc. The advent of DVD players in notebooks made this an even more attractive alternative, as travelers could carry along a DVD movie for their own personal entertainment. More and more desktop and tower microcomputers are beginning to feature DVD players as well, which further blurs the distinction between a computer and a television. One company that has taken advantage of this increase in computer-based DVD players (accompanied by a similar increase in home-entertainment DVD players) is netflix.com. This web-based business is an online substitute for a video rental store. Netflix members pay a fixed amount per month for as many movie DVDs as they can order, watch, and return (in prepaid mailing envelopes) to the company.
Circuit board that converts the processor's output information into a video signal for transmission through a cable to the monitor. Why it's important: Virtually all computer users need to be able to view video output on the monitor.
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Video cards are also called "graphics cards." Many computer users, particularly game enthusiasts, often find themselves in need of upgrading to a better video card. PC Magazine is one source of product guides for components such as video cards.
Display device that takes the electrical signals from the video card and forms an image using points of colored light on the screen. Why it's important: Monitors enable users to view output without printing it out.
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People who must sit for lengthy periods of time in front of computer monitors are subject to a range of visual problems. To learn how to prevent such problems, see the Typing Injury FAQ (Frequently Asked Questions).
Special circuit board that enhances the computer's sound-generating capabilities by allowing sound to be output through speakers. Why it's important: Sound is used in multimedia applications. Also, many users like to listen to music CDs on their computers.
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Sound cards are also called "audio cards." Many computer users, particularly game enthusiasts, often find themselves in need of upgrading to a better sound card. PC Magazine is one source of product guides for components such as audio cards.
Devices that play sounds transmitted as electrical signals from the sound card.Speakers are connected to a single wire plugged into the back of the computer. Why it's important: Sound is used in multimedia applications. Also, many users like to listen to music CDs on their computers.
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Most microcomputers come with built-in speakers. However, many music enthusiasts want to upgrade to higher-quality external speakers. Epinions.com is one source that can be used by those who want to upgrade their computer's speakers. Epinions helps people by offering unbiased advice, personalized recommendations, and comparative shopping information.
Output device that produces text and graphics on paper. Why it's important: Printers provide one of the principal forms of computer output.
Knowledge in Action
Investigate the printing resources and policies of your student computer lab. Is a color printer available? Are printouts free? If so, is there a limit on how many pages you're allowed to print? Or is there a rule prohibiting printing anything not directly related to a class you're taking? If you have to pay for copies, how much is the per-page charge? Does the print quality suffice for your coursework needs? Write a paragraph or two summarizing your findings, and present them to your class.
Device that sends and receives data over telephone lines to and from computers. Why it's important: A modem enables users to transmit data from one computer to another by using standard telephone lines instead of special communications equipment.
Knowledge in Action
Determine the transmission speed (normally specified in kilobits per second) of the modem inside the computer you use. 56 K modems are the fastest telephone modems available at present.
System software helps the computer perform essential operating tasks.Why it's important: Application software cannot run without system software. System software consists of several programs. The most important is the operating system, the master control program that runs the computer. Examples of operating system software for the PC are various Microsoft programs (such as Windows 95, 98, NT, ME, and XP), Unix, Linux, and the Macintosh Operating System.
Visit one of your college's student computer labs to evaluate how up to date the computers in this lab are with respect to their operating system. First, determine which operating system(s) is being run on the lab's computers. Use the web to ascertain the year that version of the operating system was released by its manufacturer. Then research how many versions (if any) of that operating system have been released at a later date. If the operating system(s) running on the lab computers seems outdated to you, ask the lab personnel when an update is planned. Write up a one-page summary of your findings, and report them to your class.
Software that has been developed to solve a particular problem, perform useful work on general-purpose tasks, or provide entertainment. Why it's important: Application software such as word processing, spreadsheet, database manager, graphics, and communications packages are commonly used tools for increasing people's productivity.
Microsoft Office groups some of the most popular application software packages in existence. It includes four individual applications: Excel—a spreadsheet application, Word—a word-processing application, PowerPoint—a presentation graphics application, and Outlook—an email communications program. In addition to Office, Microsoft also makes several other application software products.
Ability to connect computers to one another by communications lines, so as to provide online information access. Why it's important: Connectivity is the foundation of the advances in the digital age. It provides online access to countless types of information and services.The connectivity resulting from the expansion of computer networks has made possible email and online shopping, for example.
Two-way communication; a user can respond to information he or she receives and modify the process. Why it's important: Interactive devices allow the user to actively participate in a technological process instead of just reacting to it.
The combining of several industries through various devices that exchange data in the format used by computers. The industries are computers, communications, consumer electronics, entertainment, and mass media. Why it's important: Convergence has led to electronic products that perform multiple functions, such as TVs with internet access or phones with screens displaying text and pictures.
In early 2002, Handspring announced a new produce called the Treo, a convergent device that combines a cellphone with a PDA (personal digital assistant). The Treo product line provides users with an organizer, phone, message, and web services, all in one small handheld device.
Process by which computers and processors are made smaller. Old-fashioned vacuum tubes were converted to smaller and more reliable transistors. Integrated circuits are the next development. Why it's important: Miniaturization has led to the microprocessor which can perform calculations that required large computers.
A benefit provided by development of computer technology; related to the extent of processing done by computers. Why it's important: Computers can perform data processing and complex calculations faster, due to development in speed.
Lowering trend of costs incurred while buying computers; with increased development, computers are more affordable. Why it's important: Processors cost a fraction of what they did years ago, providing the same processing power.
Technology that presents information in more than one medium – such as text, pictures, video, sound, and animation – in a single integrated communication. Why it's important: The development of the World Wide Web included use of multimedia to display pictures, videos, music, and text together.
Further development of computers, resulting in small, powerful, wireless personal electronic devices. Why it's important: Computers have become small enough to be carried around, yet retain processing speed and power.
Process of creation of information customized to the user's preferences; programs that automatically retrieve information on designated topics. Why it's important: Companies have started to use customer preferences to design their products. Newsletters are sent by companies to inform their customers of newer and further-developed products.
2. The Internet and the World Wide Web
- Choosing Your Internet Access Device and Physical Connection: The Quest for Broadband. Over the internet, data is transmitted in characters or collections of bits. This data transmission is expressed in bps (bits per second, 8 bits equal 1 character), Kbps (kilobits—thousands of bits per second), Mbps (megabits—millions), and Gbps (gigabits—billions). Data is downloaded from a remote computer to a local computer or uploaded, the reverse.
Some internet physical connections, either wired or wireless, have more bandwidth—are able to transmit more data—than others. There are four principal types of internet physical connections: (1) Telephone (dial-up) modem connection is low-speed but inexpensive (up to 56 Kbps). (2) High-speed phone connections are ISDN (up to 128 Kbps), which transmits over traditional phone lines; DSL (up to 9 Mbps), also using traditional phone lines; and T1 (1.5 Mbps), a special trunk line. (3) Cable modems (Up to 50 Mbps) connect to cable TV systems. (4) Wireless systems include microwave systems, such as communications satellites or space stations (256 - 400 Kbps).
- Choosing Your Internet Service Provider (ISP). With a physical connection installed, you then need an internet service provider, a company to help you connect or log on to the internet. The ISP will assign you a username and a password, as well as an e-mailbox. The ISP's local access number for your area is called its point of presence (POP).
- How Does the Internet Work? When a user's modem connects to a modem at the ISP's location, the two modems go through a process called handshaking, whereby the fastest available transmission speed is established. ISPs either run their own data transmission lines called backbones or connect to an internet backbone through a network access point (NAP).
The key to exchanging data over the internet is the data transmission format. All computers must be able to understand the data transmission format to communicate. Protocols are a set of conventions (standards or rules), that govern the format of data transmitted electronically and thus ensure consistent format. The protocol that enables all computers to use data transmitted on the internet is TCP, or Transmission Control Protocol/Internet Protocol. TCP/IP breaks data into packets, which are the largest blocks of data that can be sent over the internet. IP is used to send the packets across the internet to their final destination, and TCP reassembles the packets in the correct order.
- Sending and Receiving Email. Four alternatives for getting and sending email are to buy email software, get the software as part of a browser or other software, get it from your ISP, and get it free (for example, from CNN.com or Yahoo!). People will send email to you at your domain, a location on the internet consisting of your user name and domain name, such as [email protected]
Email allows users to send attachments, or separate long documents, with their email messages. It also allows instant messaging, in which incoming messages are displayed at once in a window, which is a rectangular area on screen. You can exchange email from people worldwide with similar interests through list-serves, or email mailing lists.
The two basic rules of online behavior, or netiquette, are these: Don't waste people's time, and don't say anything online you wouldn't say to someone's face. In particular, you should always first consult FAQs, or Frequently Asked Questions; avoid flaming, such as insults or obscenities; and smooth communication using emoticons, which are friendly graphic symbols.
To manage your email, filters or instant organizers are recommended. In addition, you will need to know about managing spam, or unsolicited email. Finally, assume email messages are not private, since anyone could read them.
- The World Wide Web. What makes the web so graphically inviting is that it is in multimedia form—graphics, video, and audio, as well as text. What makes it easily navigable is that it uses hypertext, a system based on hypertext markup language (HTML) that uses "tags" or special instructions to provide links using words and phrases to many documents at various internet sites.
A computer with a domain name (.com, .org, and the like) is called a site,and a Website is the location of a web domain name in a computer somewhere on the internet. A web page is a document (with text, pictures, sound) on the web; the first page on the web site is the home page. A Web browser, software for viewing and connecting to web pages, is used to connect with the web site's address, or Uniform Resource Locator (URL). A URL, such as http://www.nps.gov/yose/camping.htm, consists of (1) the protocol, or communication rules—in particular, HyperText Transfer Protocol (HTTP), the protocol for connecting with web servers, (2) the web server name, (3) the directory, and (4) the file (perhaps with an extension, such as htm).
To get around the web with a browser, you start out from the home page (which you can personalize or customize), then use directional features (Back, Forward, Home, Search), history lists (to keep track of where you've been), and bookmarks (to mark favorite URLs). To interact with a web page, you use your mouse to click on hyperlinks, click on radio buttons (circles in front of options), and enter content in fill-in boxes. You can also click on scroll arrows to do scrolling—move up and down the web page.
A starting point for obtaining information is a Web portal, a site (such as AOL or Yahoo!) that provides popular features such as search tools. You can check the portal's home page; use a directory or category of topics; or use a keyword, or subject word, to search for a topic. You can also use a search engine to find specific documents through keyword searches and menu choices. Search engines may be human-organized, computer-created, hybrid, or metasearch. Among the search strategies are use of quotation marks around search terms and use of operators (AND, OR, NOT, +, 2).
Multimedia on the web may require a plug-in (or player or viewer), a program on the browser that allows certain files to be played or viewed. web-site developers use applets (small multimedia programs) written in Java, a programming language for creating animated, interactive web pages. Animation is rapid sequencing of still images. Streaming video transfers data in a continuous flow. Streaming audio lets you listen to a file as it is being downloaded. Push technology, such as webcasting, automatically downloads data to your computer—customized text, video, and audio. Internet telephony allows you to make phone calls on the Net.
- The Online Gold Mine. Some of the internet resources are (1) FTP, a method for copying files; (2) Telnet, a means for connecting to remote computers; (3) newsgroups, electronic bulletin boards that take place on a special network called Usenet, which requires a newsreader (part of most browsers) to access; and (4) real-time chat (RTC), typed online discussions, which require a chat client (also part of most browsers) to initiate. (5) blogs (weblogs) serve as a publicly accessible personal journals that are maintained by individuals.
The internet offers personal resources—the ability to do online matchmaking, acquire an online education through distance learning, get health information, and amuse yourself. It also offers e-commerce, or online business activities, such as online auctions; online finance; online job hunting; and B2B commerce, for business-to-business commerce, or the exchange of goods and services directly between companies.
3. Application Software
- Application Software. There are five ways of obtaining application software. (1) You can use commercial software, which is copyrighted and is available for a fee under software license, meaning it may not be duplicated without permission. (2) You can freely duplicate public-domain software, which is not copyrighted. (3) You can use copyrighted shareware, which is distributed free but requires a fee for continued use. (4) You can use freeware, which is copyrighted but distributed free. (5) You can lease rentalware, the concept behind ASPs. To learn software you can use step-by-step tutorials or documentation.
The purpose of application software is to manipulate raw data into files of information. A file is a named collection of data or a program existing in secondary storage. Program files contain software instructions; data files contain data. Three types of data files are document files (created by word processing), worksheet files (created by spreadsheets), and database files (created by database management programs). Files can be imported or acquired from other programs and exported or sent to other programs.
Productivity software, which is designed to make users more productive, may exist in stand-alone form, such as word processing or spreadsheet programs. Or several programs may be combined in an office suite. Some productivity software exists as groupware, which several users may share online.
- Common Features of Software. The user interface is the display screen that enables user interaction with the computer via keyboard or via the mouse, which has an onscreen pointer. Special-purpose keys on the keyboard execute commands, while function keys execute commands that are specific to the software. Today's screens have a graphical user interface (GUI), in which a desktop, or main interface screen, allows you to select from icons (little pictorial symbols) or menus (lists of activities). Most icons have a rollover feature that pops up an explanation when a mouse rolls over it. Menus may be pull-down (from the screen top), cascading (explode or "fly-out" out to the right or to the left), pull-up (from screen bottom), and pop-up (anywhere on screen). Toolbars (top of screen) and taskbars (bottom) display frequently used icons and menus. The data and programs appear in a frame called a window, which can be resized or repositioned on screen. Most toolbars contain a Help command to provide answers to questions; for some specific tasks, context-sensitive help is available.
- Word Processing. Perhaps the most useful productivity program is word processing software (Microsoft Word, Corel WordPerfect), which allows you to create, edit, format, print, and store text material, using mouse and keyboard. A computer keyboard contains special-purpose keys to enter, delete, and edit data and execute commands and function keys (F1, F2, etc.) for executing commands specific to the software. Several keystrokes may be combined in one or two keystroke commands—a macro.
Three features that help you create documents are the cursor, the movable symbol on the display screen; scrolling, the ability to move up, down, or sideways through the text; and word wrap, which continues text on the next line automatically when you reach the end of a line. An outline feature enables you to show the hierarchy of headings within a document. Features for editing documents are insert and delete, undelete, find and replace, cut/copy and paste, spelling checker, style button, window controls, grammar checker, and thesaurus (for presenting alternate words).
Formatting, or determining the appearance of a document, is made easier by templates, preformatted documents, and wizards, which answer your questions and format a document. Aspects of formatting are fonts, or typefaces and type sizes; spacing and columns; margins and justification (spacing of words in a line); page numbers and page headers/footers (repeated text at top/bottom); and other formatting such as use of clip art (ready-made pictures). The manufacturer usually specifies automatically standardized format settings, or default settings. Most programs give several options for printing out documents. Documents may be saved, or preserved, in secondary storage, such as hard disk.
- Spreadsheets. The electronic spreadsheet, now simply called the spreadsheet (Microsoft Excel, Corel Quattro Pro, Lotus 1-2-3), allows you to create tables and financial schedules by entering data and formulas into rows and columns arranged as a grid. A spreadsheet file contains worksheets, or single tables, with several related worksheets collected into a workbook.
Spreadsheet grids are organized with column headings across the top, row headings down the left side, and various labels or descriptive text. Columns and rows intersect in a cell, and its position is called a cell address; several adjacent cells constitute a range. A number entered in the cell is called a value, and its location is indicated by a cell pointer or spreadsheet cursor. Formulas, or instructions for calculations, are used to manipulate data; built-in formulas are called functions. Values can be changed and then recomputed; such recalculation is an important reason for the popularity of the spreadsheet, since it allows you to do what-if analysis—to see how changing numbers can change outcomes. For specialized needs, worksheet templates, custom-designed forms, are available. A useful feature of spreadsheets is the ability to create analytical graphics, graphical forms—such as bar charts, line graphs, and pie charts—that make numeric data easier to analyze.
- Database Software. A database is a collection of interrelated files, and database software (Microsoft Access, Corel Paradox, Lotus Approach) is a program that controls the structure of a database and access to the data. The most widely used form is the relational database, in which data is organized into related tables. Each table contains records (rows) and fields (columns). The records within the various tables in a database are linked by a key field, a common identifier that is unique, such as a Social Security number.
You can find what you want with a query, locating and displaying records. Records can also be sorted, as alphabetically, numerically, or geographically. Search results can then be saved, or they can be put into different formats, printed out, copied and placed in other documents, or transmitted (as via email) to someone else. A specialized type of database software is a personal information manager (PIM), which helps you manage addresses, appointments, and to-do lists.
- Specialty Software. Among the many thousands of specialized productivity programs available, the following are important. Presentation graphics software (Microsoft PowerPoint, Corel Presentations, Lotus Freelance Graphics) uses graphics, animation, sound, and data to make visual presentations, commonly called slide shows. Design templates and content templates are available to help users get started. Material may be viewed from several perspectives (Outline, Slide, Notes Page, Slide Sorter, and Slide Show views). Presentations may be dressed up with clip art, textures, audio clips, and the like.
Financial software includes personal-finance managers, entry-level accounting programs, and business financial-management packages. Personal-finance managers (Quicken, Microsoft Money) help users track income and expenses, write checks, do online banking, and plan financial goals. Tax programs help with tax preparation and filing. Some financial programs automate bookkeeping and payroll tasks. Others help in business start-ups or in making investments.
Desktop-publishing (DTP) software (QuarkXPress, PageMaker, Microsoft Publisher) enables users to mix text and graphics to produce high-quality output for commercial printing. Users can choose various type and layout styles and can use files (text, graphics) from other programs. Drawing programs allow users to design and illustrate objects and products; painting programs allow them to simulate painting on screen.
Project management software helps users plan and schedule the people, costs, and resources required to complete a project on time.
Computer-aided design (CAD) programs are used to design products, structures, engineering drawings, and maps. CAD/CAM software—for computer-aided design/computer-aided manufacturing—allows products designed with CAD to be input automatically into an automated manufacturing system that makes the products.
4. System Software
- The Components of System Software. The three basic components of system software are the operating system, device drivers, and utility programs. An operating system is the principal component of system software. Device drivers allow input/output devices to communicate with the rest of the computer system. Utility programs provide functions (such as disk cleanup and data recovery) not supplied by other system software.
- The Operating System: What It Does. The operating system (OS) consists of the master system of programs that manage the basic operations of the computer. Features of the OS are booting, user interface, CPU management, file management, task management, formatting, and security management. (1) In booting, the OS is loaded into the computer's main memory. (2) The supervisor or kernel manages the CPU. The OS also manages the memory by partitioning, dividing the memory into foreground/background areas, and arranging the programs to be processed, in a queue. (3) In file management, the OS records the storage location of files. (4) Task management includes multitasking, which executes more than one program concurrently; multiprogramming, which concurrently executes programs of different users on a multiuser operating system; time sharing, which refers to a round-robin processing of programs of several users; and multiprocessing, which is simultaneous processing of two or more programs by multiple computers. (5) Formatting, or initializing, consists of preparing a disk to store data or programs. During formatting, concentric circles called tracks are recorded on the disk. On a formatted disk, each track is divided into sectors. Intersections of tracks and sectors are used to store address references. (6) Security management allows users to control access to their computers.
- Other System Software: Device Drivers & Utility Programs. Device drivers are specialized software programs that allow input and output devices to communicate with the rest of the computer system. Utility programs perform tasks related to the control and allocation of computer resources. They enhance existing functions or provide services not supplied by other system software programs. Tasks performed by utilities include the following: (1) A backup utility is used to make a duplicate copy of the information on your hard disk. (2) A data-recovery utility is used to restore data that has been physically damaged or corrupted. (3) The antivirus software is a utility program that scans hard disks, floppy disks, and the memory to detect viruses. (4) Data compression utilities remove redundant elements, gaps, and unnecessary data from a computer's storage space so that less space (fewer bits) is required to store or transmit data. (5) Fragmentation is the scattering of portions of files about the disk in nonadjacent areas, thus greatly slowing access to the files. A defragmenter utility program will find all the scattered files on your hard disk and reorganize them as contiguous files. (6) The Disk Scanner utility program detects and corrects certain types of common problems on hard disks and floppies and also searches for and removes unnecessary files.
- Common Operating Systems. There are three categories of platforms, or particular combinations of processors and OSs, for desktops/notebooks, for networks, and for handhelds.
The principal desktop/laptop OSs are DOS, Macintosh OS, and the Microsoft Windows series. DOS was Microsoft's original OS. The Macintosh operating system runs only on Apple Macintoshes. Microsoft Windows 95/98 and more recently Windows Me are popular for desktops and portables. The recently released Microsoft Windows XP targets home and small business users; XP is based on Windows Me and Windows 2000. Microsoft introduced a new version of Windows 2000 called the Windows Server 2003 family. This version includes the Microsoft .NET Framework, a means for building, distributing, and maintaining web services and applications.
Principal network server OSs are NetWare from Novell; Windows NT and its successor Windows 2000 from Microsoft; Unix, available in several versions, including Sun's Solaris and BSD; and Linux, a free version of Unix and a kind of open-source software modifiable by anyone.
Principal OSs for handhelds are Palm OS, which runs the Palm and the Visor, and Windows CE (a slimmed-down version of Windows 95), which became Pocket PC, a simpler version.
- The OS of the Future. A distributed system is a noncentralized network of several computers and other devices that can communicate with one another.
Open-source software is gaining ground in three important areas: (1) Countries in Asia, Europe, and Latin America – including China and Germany—are now encouraging government agencies to use open-source software, particularly Linux. (2) Small companies, such as California guitar, and Zumiez, have opted to use Linux because it allows them to exclude certain programs, such as word processors or web browsers that are not an option with Microsoft. (3) Schools are able to link old PCs to a Linux server, thus making word processing, spreadsheets, slide presentations, email, calendaring, and web-browser programs available for free.
5. Hardware: The CPU and Storage
- Microchips, Miniaturization, & Mobility. Computers used to be made from vacuum tubes. Then came the tiny switches called transistors, followed by integrated circuits, which embody solid-state technology. Solid state means that the electrons travel through solid material – in this case, silicon, an element that is widely found in clay and sand and that is a semiconductor, material whose electrical properties are intermediate between a good conductor of electricity and a nonconductor of electricity. Integrated circuit chips, or microchips, are printed and cut out of "wafers" of silicon. The microcomputer microprocessors, which process data, are made from microchips. They are also used in other instruments, such as phones and TVs.
- The System Unit. The basis of the processing part of the computer is the binary system, which has only two digits: 1 and 0. These two digits, called bits, correspond to the on and off states of electricity used in computers. A group of 8 bits, called a byte, represents one character in the computer. Storage capacities are expressed in multiples of bytes: about 1,000 bytes = 1 kilobyte; about 1 million bytes = 1 megabyte; about 1 billion bytes = 1 gigabyte; about 1 trillion bytes = 1 terabyte; about 1 quadrillion bytes = 1 petabyte. Letters, numbers, and special characters are represented within a computer by binary coding schemes, such as ASCII, the code most widely used in microcomputers; EBCDIC, used with large computers; and Unicode, a subset of ASCII that uses 16 bits for each character. A parity bit is an extra bit attached to the end of a byte for purposes of checking for accuracy. Each computer brand has its own type of machine language, a binary-type programming language that the computer can run directly, which is why one type of computer can't run the software from another type of computer.
The system unit, or case, houses the motherboard, processor chip, memory chips, and power supply. The system unit also includes storage devices, such as disk drives, which are housed on shelves called bays. The motherboard contains sockets for expansion-for adding new components, such as video cards – or upgradingg – for changing to more powerful components, such as more memory chips. To protect it from damage from too much or too little power, a computer should be plugged into a surge protector or voltage regulator and also into a UPS, a battery-operated device that temporarily provides electricity if there is a power failure.
The microprocessor: The most fundamental part of the motherboard, the microprocessor is the miniaturized circuitry storing the program instructions that manipulate data into information. Two architectures for microprocessors are CISC chips, used mostly in PCs and mainframes, and RISC chips, used mainly in workstations. Most personal computers today use either Intel-type chips for PCs (made by Intel, AMD, Cyrix, and others for Compaq, Dell, Gateway, Hewlett-Packard, and IBM) and Motorola-type chips (made by Motorola for Apple Macintosh computers). Chipsets enable CPUs to communicate with the rest of the PC.
The speed of a microprocessor is determined by its system clock. For microcomputers, processing speeds are measured in megahertz (million cycles per second) or gigahertz (billion cycles). For workstations, such speeds are measured in MIPS (millions of instructions per second); for supercomputers, in flops (floating-point operations per second); and for all computers, in fractions of a second (milliseconds, microseconds, nanoseconds, and picoseconds). Another measure, word size, is the number of bits a computer can process at any one time, with 64 bits being faster than 32 bits.
A processor, also called a CPU (central processing unit), follows the instructions of the software (program) to manipulate data into information. The CPU consists of the control unit, which deciphers each instruction stored in it and then carries it out, and the arithmetic logic unit (ALU), which performs arithmetic and logical operations. For every instruction, the control unit carries out four basic operations, known as the machine cycle. Both the control unit and the ALU contain registers, high-speed storage areas that temporarily store data during processing. Data transmission within the CPU and between the CPU and other components of the motherboard is by means of electrical roadways called buses.
Memory: Also on the motherboard are memory chips, of which there are four types: RAM, ROM, CMOS, and flash. (1) RAM (for random access memory) chips temporarily hold software instructions and also data before and after processing by the CPU. RAM is volatile; its contents are lost when the power goes off. Five types of RAM chips are DRAM, which must be constantly refreshed by the CPU or it will lose its contents; SDRAM, which is faster than DRAM; SRAM, also faster than DRAM and able to retain its contents without being refreshed by the CPU; RDRAM, which is faster and more expensive than SDRAM; and DDR-SDRAM, which is used in notebook computers. The newly found non volatile forms of RAM are magnetic RAM (M-RAM), which uses minuscule magnets to store binary data and ovonic unified memory (OUM) which generates different levels of resistance to store bits. RAM chips often appear on memory modules – SIMM has chips on one side, DIMM has chips on both sides – that can be plugged into expansion slots on the motherboard. (2) ROM (for read-only memory) chips contain fixed start-up instructions. (Read means to transfer data from an input source to the CPU or memory; write means to transfer data from the CPU or memory to an output device.) A variant is PROM, a ROM chip that allows users to load read-only programs and data, although only once. (3) Battery-powered CMOS chips don't lose their contents when the power is turned off; this quality makes them useful for holding times and dates. (4) Flash memory chips can be erased and reprogrammed more than once.
The processor searches for data or program instructions in the following order: first level 1 cache, then level 2 cache, then RAM, then hard disk (or CD-ROM). Cache temporarily stores instructions and data that the processor is likely to use frequently, thereby speeding up processing. Level 1 cache is built into the processor chip; level 2 cache resides outside the processor chip and consists of SRAM chips. Virtual memory is hard-disk space used to extend the capacity of RAM.
Methods of Speeding up Processing: Processing speed can accelerated by making use of the following methods: (1) Interleaving that is used in large systems. (2) Bursting that is used to provide the CPU with more data. (3) Pipelining that is used in division of tasks. (4) Superscalar architecture and hyperthreading that is used to treat the microprocessor as though it is two microprocessors.
Ports and cables: A port is a connecting socket on the outside of the system unit into which are plugged different kinds of cables. Seven types of ports are as follows: (1) Serial ports transmit bits one after the other, or slow data over long distances. (2) Parallel ports transmit 8 bits simultaneously, or fast data over close distances, as to printers. (3) SCSI ports transmit 32 bits simultaneously in a daisy chain of up to seven devices linked in a series. (4) USB ports are general-purpose ports that transmit data to up to 127 devices in a daisy chain. USB permits Plug and Play, which allows peripheral devices and expansion cards to be automatically configured while they are being installed. (5) Firewire ports to improve PC/peripheral connections. (6) Dedicated ports exist for special purposes, as for the keyboard and mouse. (7) Infrared ports enable cableless connection with infrared devices, as between the computer and some printers.
Expandability -- buses and cards: Closed architecture means a personal computer has no expansion slots; open architecture means it does. Expansion slots are sockets on the motherboard into which may be plugged expansion cards, circuit boards that provide more memory or that control peripheral devices. Expansion slots are connected to the CPU by expansion buses, such as ISA, the oldest and slowest at 8 or 16 bits; PCI, faster at 32 or 64 bits; and AGP, twice as fast as PCI and designed to support video and 3-D graphics. Types of expansion cards include the following: Graphics cards convert data into video images to display on a monitor. Sound cards transmit digital sounds; this includes music for video games created by wavetable synthesis, digitized sound samples taken from recordings of actual instruments. Modem cards are modems installed inside the computer. Network interface cards allow data transmission over a cable network. The PC card is used principally to expand the capabilities of laptops.
- Secondary Storage. Secondary storage hardware -- devices that permanently hold data and programs -- include floppy disks, hard disks, optical disks, magnetic tape, and smart cards. Online secondary storage is also possible.
Floppy disks are flat circular pieces of mylar plastic in 3.5-inch plastic cases. Floppy disks have a write-protect notch, which can prevent accidentally recording over on a disk. Data is recorded in concentric circles called tracks; each track is divided into sectors, invisible wedge-shaped sections used for storage reference (address) purposes. In the disk drive, the read-write head transfers data between the computer and the disk. Besides 3.5-inch floppy disks, which hold 1.44 megabytes, other forms of removable disks are floppy-disk cartridges, or higher-capacity removable disks – Zip disks, SuperDisks, and HiFD disks. Zip disks are special disks with a capacity of 100 or 250 megabytes. SuperDisks have a capacity of 120 megabytes, and a SuperDisk drive can also read 1.44-megabyte floppies. HiFD disks have a capacity of 200 megabytes; the disk drive can also read 1.44-megabyte floppies.
Hard disks are thin but rigid metal platters covered with a substance that allows data to be held in the form of magnetized spots. Disks are sealed in a hard-disk-drive unit, which can be quite sensitive, susceptible to a head crash, when the surface of the disk touches particles or the read/write head, resulting in loss of data on the disk. Hard disks may be nonremovable or removable. (1) A nonremovable hard disk is housed in the microcomputer system unit and stores most programs and data. Ads for hard disks may specify the hard-disk controller, a circuit board that positions the disk and read/write heads. Popular hard-disk controllers are Ultra ATA (also known as EIDE), which allows fast data transfer and high storage capacity, and SCSI, which supports several disk drives as well as other peripheral devices. (2) A removable hard disk (Iomega's Jaz, SyQuest's SparQ) consists of one or two platters enclosed with read/write heads in a hard plastic case, which is inserted into a microcomputer's cartridge drive.
Large computer systems also have three types of secondary-storage devices: (1) A removable-pack hard-disk system contains 6-20 hard disks, of 10.5- or 14-inch diameter, aligned one above the other in a sealed unit. (2) Fixed-disk drives are high-speed, high-capacity disk drives that are sealed in their own cabinets. (3) A RAID (redundant array of inexpensive disks) storage system, which consists of two or more disk drives within a single cabinet or connected along a SCSI chain, sends data to the computer along several parallel paths simultaneously.
Optical disks are removable disks on which data is written and read through use of laser beams. Types of optical disks are CD-ROM, CD-R, CD-RW, DVD-ROM, DVD-R, DVD-RW, and DVD-RAM. CD-ROM is a read-only disk that holds prerecorded text, graphics, and sound. CD-R disks can be written to once but can be read many times. CD-RW disks can be written to and erased so the disk can be reused several times. DVD-ROM is a high-capacity CD, storing up to 17 gigabytes. DVD-R disks allow one-time recording by consumers. DVD-RW (for rewritable) and DVD-RAM (for random access memory) can be recorded on and erased more than once.
Flash memory cards, or flash RAM cards, consist of circuitry on credit-card-size cards that can be inserted into slots connecting to the motherboard. Small Flash-based "keychain" memory units plug into USB ports of almost any new PC or notebook.
Magnetic tape is thin plastic tape coated with a substance that can be magnetized, with data represented by magnetized (1s) or unmagnetized (0s) spots. Large computers tend to use magnetic-tape reels: small computers tend to use tape cartridges, resembling audiocassettes. A smart card, such as a telephone debit card, contains a microprocessor and memory chip. An optical card is a laser-recordable, wallet-type card used with an optical card reader. A final type of storage is online secondary storage, in which secure online services provide backup storage.
- Future Developments in Processing & Storage. On the far horizon in processing are technologies using nanotechnology, optical computing, DNA computing, quantum computing, and molecular and dot computers. As for secondary storage, one noteworthy development is that of higher-density disks, such as a hard drive capable of holding 56 gigabytes per square inch. In the future we may also see innovations in molecular electronics, storage at the subatomic level, as in the use of holograms, microscopic magnets one molecule in size, subatomic lines, and even bacteria. We may also see online "storewidth," combining storage and bandwidth.
6. Hardware: Input and Output
- Input & Output. Input Hardware consists of devices that translate data into a form the computer can process. The people-readable form of the data may be words, but the computer-readable form consists of binary 0s and 1s, or off and on electrical signals. Output Hardware consists of devices that translate information processed by the computer into a form that humans can understand. Such output may be in the form of words, numbers, sounds, and pictures.
- Input Hardware. Input Hardware may be divided into three categories: keyboards, pointing devices, and source-data entry devices.
Keyboards: Keyboards are devices that convert characters into electrical signals readable by the processor. There are two categories of keyboards. The first is the traditional computer keyboard, which has all the keys of a typewriter plus some that are unique. The second category, specialty keyboards and terminals, includes three types of terminals: (1) A dumb terminal has a screen and a keyboard and can input and output but not process data. (2) An intelligent terminal has a screen, a keyboard, and its own processor and memory. One example is the automated teller machine (ATM), the self-service banking machine. Another is the point-of-sale (POS) terminal, used to record purchases in a store. (3) An internet terminal provides access to the internet. Examples are set-top boxes or Web terminals, stripped-down network computers, online game players, PC/TVs, and handheld wireless pocket PCs or personal digital assistants (PDAs).
Pointing Devices: Pointing devices control the cursor or pointer on a screen and allow the user to select options displayed on the screen. They include the mouse and its variants, the touch screen, and various forms of pen input. (1) The mouse, which directs a pointer on the display screen, maneuvers a ball with the help of the surface on which the mouse is slid. Variants are the trackball, a movable ball mounted on a stationary device; the pointing stick, which protrudes from the keyboard; and the touchpad, a surface over which you move your finger. (2) The touch screen is a display screen that is sensitive to touch. (3) Devices for pen input include pen-based computer systems, in which users write with a pen-like stylus on a screen; light pens, light-sensitive pen-like devices; and digitizers, which convert drawings to digital data – one example is the digitizing tablet.
Scanning & Reading Devices: Source-data entry devices create machine-readable data on magnetic media or paper, or feed it directly into the computer's processor. These include various scanning devices like bar-code readers, mark- and character-recognition devices, and fax machines; audio and video input devices (digital cameras); sensors; radio-frequency identification devices; and human-biology input devices. (1) Scanners use laser beams and reflected light to translate images of text, drawings, and photographs into digital form. One of the most famous types of scanners is the flatbed scanner that works like a photocopier. Scanning technology has ushered in the new industry of electronic imaging. Another scanning device is the bar code reader, which reads the zebra-striped barcodes on products to translate them into digital code. Magnetic-ink character recognition (MICR) reads check numbers; optical mark recognition (OMR) reads pencil marks; optical character recognition (OCR) reads preprinted characters, such as those on store price tags. The fax machine, the last type of scanner, reads images and sends them over phone lines. Dedicated fax machines only send and receive fax documents; fax modems are modems with fax capabilities. (2) Audio-input devices translate analog sounds (those with continuously variable waves) into digital 0s and 1s, either through audio boards or MIDI boards. (3) Video-input cards translate analog film and videotape signals into digital form, using either frame-grabber video cards or full-motion video cards. (4) Digital cameras use light-sensitive processor chips to capture photographic images in digital form. (5) Speech-recognition systems process signals by comparing electrical patterns produced by voices, with prerecorded patterns stored in a computer. (6) Sensors collect data directly from the environment and transmit it to a computer. (7) Radio-frequency identification (or RF-ID tagging) is based on an identifying tag bearing microchip that contains code numbers; these numbers are read by radio waves of a scanner linked to a database. (8) Human-biology input devices include biometric systems, which use biometrics, the study of body characteristics, to identify people.
- Output Hardware. Output hardware converts machine-readable information into people-readable form. Three common types of outputs are softcopy, hardcopy, and other.
Softcopy: Softcopy refers to printed data that is not printed, such as that shown on a display screen. A display screen (monitor, screen) shows programming instructions and data as they are being input and information after it is processed. Screen clarity is affected by dot pitch, or space between pixels (the small units on screen that can be turned on or off); by resolution, which involves the number of pixels per square inch; color depth, which is the amount of information expressed in bits, that is stored in a dot; and by refresh rate, the number of times per second pixels are recharged. Two common types of monitors are CRT and flat-panel. A CRT (cathode-ray tube) is a vacuum tube. A flat-panel display consists of two plates of glass separated by a layer of a substance in which light is manipulated; one technology is liquid crystal display (LCD), in which molecules of liquid crystals create images by transmitting or blocking light. Flat-panel screens are either active-matrix display, in which a unique transistor controls each pixel on the screen, or passive-matrix display, in which a transistor controls a row or a column of pixels. The common color and resolution standards for monitors are SVGA (the most common), which can produce 16 million possible colors, XGA, which can produce 65,536 possible colors, SXGA which is used by graphic designers and programmers, UXGA which can support up to 16.8 million colors, and QXGA which is used for large LCD screens for computer users needing to view extreme details.
Hardcopy: Hardcopy refers to a printed output. A printer prints characters or images on paper or some other medium. Resolution of the image is measured by dpi (dots per inch), with more dots producing greater sharpness. The two types of printers are Impact printers and nonimpact printers. Impact printers form images by striking a print hammer or wheel against an inked ribbon, leaving an image on paper; one type is the dot-matrix printers, which contains a print head of small pins. Nonimpact Printers form characters or images without direct physical contact between printing mechanism and paper. The three types of nonimpact printers commonly used are laser, ink-jet, and thermal. A laser printer creates images with dots like a photocopying machine; the printer uses a page description language, software that describes the images to the printer. An ink-jet printers sprays electrically charged droplets of ink at high speed onto paper. A thermal printer uses colored waxes and heat to burn dots onto special paper. A special kind of printer, the plotter, which may be ink-jet or electrostatic, produces high-quality graphics, such as maps, that are too large for regular printers. Another category of printer is the multifunction printer, which combines printing, scanning, copying, and faxing in one device.
Other Output: Other forms of output are sound, voice, and video. Sound-output devices produce digitized sound. Voice-output devices convert digital data into speech-like sounds. Video consists of photographic images, played at 15-29 frames per second; in one form of video output called videoconferencing people have online meetings using computers and communications devices that enable them to see and hear one another.
- The Future of Input & Output. Increasingly, input will be performed in remote locations and will rely on source data automation. Future source data automation will include high-capacity bar codes, 3-D scanners, more sophisticated touch devices, smarter smart cards, more diverse sensors, better voice recognition, smaller electronic cameras, more sophisticated biometric devices, and even brainwave input devices.
Output, too, is being performed in remote locations. On the horizon are better, cheaper, and larger display screens; higher-fidelity audio using wavetable synthesis and three-dimensional sound; and "real-time" video using digital wavelet theory. Thanks to 3-D technology, three-dimensional images can appear on computer displays and, through VRML software, users of the World Wide Web can experience 3-D "virtual worlds."
- Input & Output Technology & Quality of Life: Health & Ergonomics. The use of computers and communications technology can have important effects on our health. Some of these are repetitive stress (strain) injuries (RSIs) such as carpal tunnel syndrome; computer vision syndrome, such as eyestrain and headaches; and back and neck pains. Some people are concerned about electromagnetic fields (EMFs), waves of electrical and magnetic energy emitted from CRTs, cellphones, and the like.
Negative health effects have increased interest in the field of ergonomics, the study of the relationship of people to a work environment.
7. Networks and Communications
- From the Analog to the Digital Age. Computers use digital signals, which present information in a binary way. Most other systems, such as traditional telephones and TV, use analog signals, which continuously vary in strength of quality. A modem converts digital signals into analog signals, so that computer signals can be sent over phone lines.
- The Practical Uses of Communications. There are many forms of connectivity, or communications connections. (1) Videoconferencing, the linking of people through TV, video, and sound, by using point-to-point or multipoint arrangements, is useful for long-distance meetings. (2) Workgroup computing, in which microcomputer networks enable workers to cooperate on projects, allows people to work on the same information at the same time. (3) Telecomputing, working at home with telecommunications, can increase productivity and decreases costs for employers and employees. (4) Virtual offices, nonpermanent, mobile offices that run with telecommunications and computers, add workplace flexibility. (5) Home networks enable households to link and share all kinds of peripheral devices and internet services. (6) Smart television consists of digital television (DTV) (DTV), high-definition television (HDTV), and standard-definition television (SDTV). DTV uses a digital signal, or series of 0s and 1s. The high-resolution type of DTV is HDTV. An alternate DTV is standard-definition television (SDTV), which allows broadcasters to transmit more information within the HDTV bandwidth so that they can broadcast six channels instead of one.
- Communications Channels. The following factors affect how data is transmitted.
The electromagnetic spectrum consists of fields of electrical energy and magnetic energy, which travel in waves. A part of the electromagnetic spectrum is the radio frequency spectrum, fields of electrical and magnetic energy that carry communications signals, which vary according to frequency. A range or a band of frequencies that a transmission can carry in a given period of time is called bandwidth. The wider the band, the faster data can be transmitted. Broadband connections are very high speed.
A communications channel is the path over which information travels in a telecommunications system. Channels may be wired or wireless.
Three types of wired channels are the following. (1) Twisted-pair wire, or standard telephone wire, consists of two strands of insulated copper wire twisted around each other; it is used for both voice and data transmission. (2) Coaxial cable consists of insulated copper wire wrapped in other materials; it is better than twisted-pair for resisting noise. (3) Fiber-optic cable consists of thin strands of glass or plastic that transmit beams of light rather than electricity; it is very fast and noise-resistant.
Four types of wireless channels are the following. (1) Infrared transmission sends data via infrared-light waves. (2) Broadcast radio sends data over long distances, between states, regions, and countries. (3) Microwave radio transmits voice and data as superhigh-frequency radio waves. (4) Communications satellites are microwave relay stations in orbit around the earth. They occupy one of the three zones in space: GEO, MEO, or LEO.
Types of long-distance wireless communications may be one-way or two-way. Examples of one-way communication are (1) Global Positioning Satellite (GPS), which consists of satellites that can be used to identify earth locations identified by GPS signal receivers, and (2) pagers, radio receivers that receive data from special radio transmitters. Examples of two-way communication are (1) two-way pagers; (2) analog cellphones, designed for communicating by voice through a system of cells, each 8 miles or less in diameter and served by a transmitter-receiving tower; (3) digital wireless services, supports digital cellphones and personal digital assistants, uses a network of cell towers to send voice communications and data over the airwaves in digital form; and (4) broadband wireless digital services, which are able to transmit data at high speed, provide web access, and display color video and still pictures and play music.
Short-range wireless communication standards include (1) Bluetooth, a short-range wireless digital standard aimed at linking cell phones, PDAs, computers, and peripherals up to distances of 30 feet, and (2) WiFi, a short-range wireless digital standard aimed at helping portable computers and handheld wireless devices to communicate at high speeds and share internet connections at distances up to 300 feet. It connects through access points to a kind of local area network known as the Ethernet.
Compression is a method of removing repetitive elements from a file so that it requires less time to transmit. At the receiving end, the file is usually decompressed—the repeated patterns are restored. Two methods of compression are lossless and lossy. Lossless compression uses mathematical techniques to replace repetitive patterns of bits with a kind of coded summary. When they are decompressed, the bits are restored, so that the data is the same as what went in—important in computer data, databases, spreadsheets, and word processing files. Lossy compression permanently discards some data during compression; it is often used for graphics files and sound files. Two compression standards are JPEG, for still images, and MPEG, for moving images.
- Factors Affecting How Data is Transmitted. Several factors affect how data is transmitted. (1) Line configurations are the methods whereby communications lines are connected. A point-to-point line directly connects the sending and receiving devices, whereas a multipoint line is a single line that interconnects several communications devices to one computer. (2) Serial transmission transmits the bits sequentially; parallel data transmission transmits bits through separate lines simultaneously. (3) Data can flow in three ways: simplex (one way); half-duplex (in both directions but not at the same time); and full-duplex (in both directions simultaneously). (4) The transmission mode can be either asynchronous or synchronous. In asynchronous transmission, data is sent one byte at a time, with a "start" bit and a "stop" bit. With synchronous transmission, data is transmitted in blocks, with a start and a stop bit pattern to delineate each block. (5) In circuit switching, the transmitter has full use of the circuit until all the data has been transmitted and the circuit is terminated. In packet switching, electronic messages are divided into packets for transmission over a wide area network to their destination, through the most expedient route. (6) The efficiency of data transmission can be increased by transmitting multiple signals over a single communications channel, a process known as multiplexing. Multiplexing devices include multiplexers, concentrators, and front-end processors. (7) A protocol is a set of conventions that control the exchange of data between hardware and/or software components in a communications network. (8) OSI is an international standard that defines seven layers of protocols for worldwide computer communications.
- Networks. A communications network is a system of interconnected computers, phones, or other communications devices that can share applications and data. Networks enable people to share peripheral devices, programs, and data; provide better communications; help to secure information; and provide access to numerous databases.
Types of networks are as follows. A wide area network (WAN) covers a wide geographical area, such as a country. A metropolitan area network (MAN) covers a city or suburb. A local area network (LAN) covers a limited area such as an office or a building. Most large networks have a host computer, a mainframe or midsize central computer to control the network. Any device attached to a network is called a node. MANs and LANs may be connected to the internet by a high-speed network called a backbone.
Two types of LANs are client/server and peer-to-peer. A client/server LAN consists of microcomputers that request data (clients) and powerful computers that provide data (servers). A file server, for example, stores programs and data files; other servers are database server, print server, web server, and mail server. In a peer-to-peer LAN, there is no server; microcomputers on a network communicate with each other directly. Several standard components of a LAN are the connection or the cabling system, microcomputers with network interface cards (NIC), network operating system (Novel NetWare, Microsoft Windows NT/2000, Unix, or Linux), and other shared devices (printers, storage devices). Other components are a router, a special computer that helps to communicate messages when networks are tied together; a bridge, an interface used to connect the same types of networks; a gateway, an interface that allows communication between dissimilar networks; and a hub, a common connection point for devices in a network.
Networks can be laid out in three different topologies, or shapes: star, ring, and bus. In a star network, all devices are connected to a central server. In a ring network, all devices are connected in a bus network. In a bus network, all devices are connected to a common channel.
Organizations now use two variant networks that use the internet's infrastructure and standards. One is an intranet, an organization's internal private network for employee use. The other is an extranet, for selected suppliers and other strategic parties as well as employees. Security for such networks is maintained through a firewall, a system of hardware and software that blocks unauthorized users inside and outside the organization. In order to minimize communication costs, some companies have established VPN (Virtual private Networks), private networks that use a public network to connect remote sites.
- The Future of Communications. Some of the new developments in communications are (1) Satellite-based systems consisting global high-speed satellite networks that will permit users to exchange a broader range of data, including internet pages and videophone calls, anywhere in the world. (2) 4G (Fourth Generation) wireless technology is currently being researched by Hewlett-Packard and a Japanese telecommunications company even before 3G radio spectrum is available in the U.S. (3) Photonics, the science of sending data bits by means of light pulses carried on glass fibers, would enable more light signals to be carried on fiber-optic lines. (4) In grid computing, the grid refers to the linking of many servers into a single system for the purpose of breaking down complex computing tasks and doing work previously possible only with supercomputers. Geologists use grid networks in a limited way to simulate the effects of earthquakes, and biochemists use it to simulate virus attacks on the human body.
- Cyberethics. Three important issues of cyberethics are as follows. (1)To protect children against access to controversial material, parents may employ blocking software that screens objectionable material based on keywords; browsers may contain built-in ratings for internet and web use; and the V-chip, which allows the screening of TV programs high in violence and sex.
8. Files, Databases, and E-Commerce
- Managing Files: Basic Concepts. A database is a logically organized collection of related data designed and built for a specific purpose. Data is organized in a data storage hierarchy of increasingly complex levels: bits, bytes (characters), fields, records, files, and databases. A bit is the smallest unit of data that the computer can store in a database – represented by 0 for off or 1 for on. A character is a letter, number, or special character. A field consists of one or more characters (bytes). A record is a collection of related fields. A file is a collection of related records. A database is, as mentioned, an organized collection of integrated files. Important to data organization is the key field, a field used to uniquely identify a record so that it can be easily retrieved and processed.
Files are given names—filenames. Filenames also have extension names, three-letter additions such as .doc and .txt. Among the types of files are the following. (1) Program files are files containing software instructions. The two most important are source program files, which contain instructions in the form written by the programmer, and executable files, which contain instructions that tell a computer how to perform a particular task. (2) Data files are files that contain data, and are categorized into two types: master files, which contain relatively permanent records that are updated periodically; and transaction files, that hold all changes to be made to the master file. (3) Other common files are ASCII files, image files, audio files, animation/video files, web files, desktop publishing, drivers, and Windows operating system files.
Two main ways in which a storage device accesses stored data are sequential access and direct access. Sequential storage means that data is stored and retrieved in sequence, as is the case with magnetic-tape storage. Direct access storage means that a computer can go directly to the information you want, as in a CD player; hard disks and other types of disks are of this nature.
Whether on magnetic tape or disk, data may be stored offline or online. Offline storage means that data is not directly accessible for processing until the tape or disk has been loaded onto an input device. Online storage means that stored data is randomly (directly) accessible for processing.
- Database Management Systems. A database management system (DBMS) consists of programs that control the structure of a database and access to the data. The benefits of databases are reduced data redundancy, improved data integrity, increased security, and ease of data maintenance. Databases can be classified as two types. (1) An individual database, or single-user database, is a collection of integrated files used by one person. It could be a personal information manager, which helps people keep track of information they use daily. (2) A multiuser database, or centralized database, is shared by users in one organization in one location. A distributed database is shared by many users but is stored on different computers operating as equals in different locations. Large databases are managed by a database administrator, who coordinates all related activities and needs for an organization's databases.
- Database Models. Databases can be organized in four ways. (1) In a hierarchical database, fields or records are arranged in related groups resembling a family tree, with child (lower-level) records subordinate to parent (higher-level) records. (2) A network database is similar to a hierarchical database but each child record can have more than one parent record. (3) A relational database relates, or connects, data in different files through the use of a key field. Structured query language is an easy-to-use computer language for making queries to a relational database and for retrieving selected records. One feature of most query languages is query by example (QBE), which allows users to ask for information in a relational database by using a sample record to define the qualifications they want for selected records. (4) An object-oriented database uses objects, software written in small, reusable chunks, as elements within database files. An object consists of data in any form and instructions on the action to be taken on the data.
- Features of a Database Management System. A database management system may have a number of components. (1) A data dictionary, also called a repository is a procedures document or disk file that stores the data definitions or a description of the structure of data used in the database. (2) DBMS utilities are programs that allow you to maintain the database by creating, editing, and deleting data, records, and files. (3) A report generator is a program for producing an onscreen or printed document from all or part of a database. (4) Different users are given different user access privileges, as determined by the database administrator. (5) A DBMS should have system recovery features, so the database administrator can recover the contents of the database in the event of hardware or software failure. Four approaches are: mirroring, with two copies of the database in different locations; reprocessing, in which the processing can be redone from a known past point; rollforward, a variant on reprocessing; and rollback, which is used to undo unwanted changes to the database.
- Databases & the New Economy: E-Commerce, Data Mining, & B2B Systems. Databases underpin the so-called New Economy of computer, telecommunications, and internet companies in three ways: e-commerce, data mining, and business-to-business (B2B) systems.
E-commerce, or electronic commerce, is the buying and selling of products and services through computer networks; an example is Amazon.com.
Data mining is the computer-assisted process of sifting through and analyzing vast amounts of data in order to extract meaning and discover new knowledge. Data mining begins with acquiring data and cleaning it of errors to yield cleaned-up data and a version of it called meta-data (which shows its origins and transformations), which are then sent to a data warehouse, a special database of cleaned-up data and meta-data. Data mining is used in applications ranging from marketing to health to science.
Business-to-business systems (B2B systems) allow businesses to sell to other businesses, using the internet or private network to cut transaction costs and increase efficiencies.
- The Ethics of Using Databases: Concerns about Accuracy & Privacy. In morphing, a film image is altered pixel by pixel, so that the image becomes something else. This manipulation of digitized images and sounds raises some ethical issues. Sound performances can be misrepresented, photos may be manipulated, and video and TV images may be altered in undetectable ways and all stored in a database.
Databases are also limited in accuracy and completeness, since not all facts can be found in a database, nor are all data items true. In addition, databases raise several concerns about privacy. Finally, those who own databases may be in a position to monopolize information.
9. The Challenges of the Digital Age
- Security Issues: Threats to Computers & Communications Systems. Among the threats to the security of computers are the following. (1) Errors and accidents, such as human errors, procedural errors, software errors, electromechanical problems, and "dirty data" problems. (2) Natural hazards, such as earthquakes, hurricanes, fires, civil strife, and terrorism. (3) Computer crimes, which can be either illegal acts perpetrated against computers or the use of computers to accomplish illegal acts. Crimes against computers include theft of hardware, software, time and services, or information, or crimes of malice and destruction. (4) Crimes using computers include credit-card theft and investment fraud. (5) Worms are programs that copy themselves repeatedly into a computer's memory or disk drive, and viruses are deviant programs that can destroy data. Worms and viruses are passed by infected floppy disks, or infected data sent over a network; antivirus software can detect viruses. (6) Computer criminals may be an organization's employees, outside users, hackers and crackers, and professional criminals. Hackers gain unauthorized access to computers, often just for the challenge, whereas crackers do it for malicious purposes.
- Security: Safeguarding Computers & Communications. Security, the system of safeguards for protecting computers against disasters, failure, and unauthorized access, has four components. (1) Computer systems try to determine authorized users by three criteria: by what they have (keys, badges, signatures); by what they know (as with PINs or personal identification numbers, and passwords or codes); and by who they are (as by physical traits, as determined perhaps through biometrics, the science of measuring individual body characteristics). (2) Encryption, altering data so it is not usable unless the changes are undone, tries to make computer messages more secure. (3) Software and data are protected by controlling access to files, by audit controls that track the programs used, and by people controls that screen job applicants and other users. (4) Disaster-recovery plans are methods for restoring computer operations after natural disasters or accidents.
- Quality-of-Life Issues: The Environment, Mental Health, & the Workplace. Some quality-of-life issues related to information technology are as follows. (1) Environmental problems include manufacturing and disposing by-products, environmental blight, and possible risks of nanotechnology. (2) Computer-related mental-health problems include isolation, online gambling, and stress. (3) Problems affecting workplace productivity include misuse of technology, as when employees waste company time going online for personal purposes; fussing with computers because of hardware/software problems; and information overload.
- Economic Issues: Employment & the Haves/Have-Nots. Two charges by economic critics of information technology are as follows. (1) Technology replaces humans in countless tasks, forcing millions of workers into temporary or part-time employment, and even unemployment. (2) Technology widens the gap between the rich and the poor, between information "haves" and "have-nots."
- The Digital Environment: Is There a Grand Design? Some factors affecting the shape of the digital environment are as follows. (1) Internet2 is a cooperative university-business program to enable high-end users to quickly move data. (2) The 1996 Telecommunications Act was designed to increase competition among telecommunications businesses by allowing different carriers to offer the same services. (3) ICANN is the Internet Corporation for Assigned Names and Numbers, which is a nonprofit corporation established to regulate internet domain names. (4) The unruly nature of the internet has led to the emergence of company intranets and extranets to provide reliability.
10. The Promises of the Digital Age
- Emerging Global Telecommunications. Two models of telecommunications are prevalent. In the tree-and-branch telecommunications model, a centralized information provider sends out messages through many channels to many consumers, as in many mass media. In the switched-network telecommunications model, people on the system are not only consumers of information but also possible providers of it; this model, embodied in the internet, is much more participatory.
- Artificial Intelligence. Artificial intelligence (AI) consists of technologies used for developing machines to emulate human qualities. It includes the following: (1) Natural language processing is the study of ways for computers to recognize and understand human language. (2) Expert systems are interactive computer programs used to solve problems normally requiring the assistance of human experts. An expert system has three components: a knowledge base, a database of knowledge about a particular subject; an inference engine, the software that controls the knowledge base and produces conclusions; and a user interface. (3) An intelligent agent is a form of smart software, or software with built-in intelligence that monitors work patterns, asks questions, and performs work tasks on the behalf of the user. (4) Pattern recognition involves a camera and software that identify recurring patters in what they are seeing and recognize the connections between the perceived patterns and similar patterns stored in a database. (5) Fuzzy logic is a method of dealing with imprecise data and uncertainty, with problems that have many answers rather than one. (6) Virtual reality, devices that project a person into a sensation of three-dimensional space, is used in arcade-type games and also in simulators, devices that represent the behavior of physical or abstract systems and are used in training, as of airplane pilots. (7) Robotics, the development and study of machines that can perform work normally done by people, has produced robots, automatic devices that perform functions usually performed by people.
There are two approaches to artificial intelligence are weak AI and strong AI. Weak AI makes the claim that computers can be programmed to simulate human cognition. Strong AI makes the claim that computers can be made to think on a level that is at least equal to humans and possibly even be conscious of themselves. Types of strong AI are Neural networks, Genetic algorithms, and cyborgs.
Artificial life is the study of "creatures" computer instructions, or pure information that, like live organisms, are created, replicate, evolve, and die. A-life raises the question of how we can know when computers can be said to possess "intelligence" or "self-awareness." One answer is suggested by the Turing test, in which a human judge converses by means of a computer terminal with two entities one a person, one a computer hidden in another location, to try to determine which seems to have the most human qualities.
- Information & Education. The challenge of making sense of vast stores of information is being addressed with intelligent agents, programs that roam networks and compile data and perform work tasks on your behalf. In education, students at all levels are finding computers helpful. Their use in distance learning over the internet is increasing.
- Health, Medicine, & Science. Telemedicine, medical care delivered via telecommunications, is one way computers and communications are changing health and medicine. The digitizing of medical information is affecting everything from psychotherapy to implants. Patients' use of health-care databases is changing their relationship with doctors. A new idea in science is the "collaboratory," an internet-based collaborative laboratory of researchers around the world, such as that among space physicists. In archaeology, computer technology may be used to avoid invasive excavations.
- Commerce & Money. Information technology erases boundaries in business between company departments, suppliers, and customers. Consequently, the idea of what constitutes an organization is changing. There are new developments in sales and marketing and retailing, as with online sales, and in banking and e-money, stock trading, and manufacturing.
- Entertainment & the Arts. Information technology is producing changes in music and movies. In music, new digitized instruments offer a wide range of sounds, while the internet is reshaping the marketing of songs. In movies, computers are used for all kinds of animation and other special effects; digital equipment permits better film editing, and enables amateurs to make movies more cheaply.
- Government & Electronic Democracy. The internet has potential for civic betterment because it is free of government intrusion, is fast and cheap, and facilitates communication among citizens. Examples are found in cities in California, Colorado, Texas, and Nevada. Online voting has been tried and may be expanded. The government itself is making increasing use of computers, as in electronic tax filing.
- Jobs & Careers. Job seekers can now use employer databases to get leads on jobs, and they can post résumés with electronic job registries so employers can find them. The five information-technology job categories projected to have the largest percentage increase in the near future are computer engineers, computer support specialists, systems analysts, database administrators, and desktop publishing specialists.
11. Information Systems
- Organizations, Managers, & Information. To understand how information flows in an organization, we need to understand how organizations work. Information flows horizontally between the six departments of an organization: research and development, production, marketing, accounting and finance,human resources, and information services. It also flows vertically between the layers of managements.
There are three levels of management corresponding to three kinds of decisions, as reflected in the organization chart, a schematic drawing showing the hierarchy of formal relationships amongst organizations' employees. (1) Top managers are concerned with long-range, or strategic, planning and decisions. (2) Middle-level managers, make tactical decisions to implement the strategic goals of the organization. (3) Supervisory managers make operational decisions, predictable decisions that can be made by following a well-defined set of routine procedures.
Information has three distinct properties: level of summarization, degree of accuracy, and timeliness. To make the appropriate decisions strategic, tactical, and operational, the different levels of managers need the right kind of information: structured, semistructured, and unstructured. Structured information is detailed, current, concerned with past events, records a narrow range of facts, and covers an organization's internal activities. Unstructured information is summarized, less current, concerned with future events, records a broad range of facts, and covers activities outside as well as inside an organization. Semistructured information includes some structured information and some unstructured information.
- Computer-Based Information Systems. Seven types of computer-based information systems that provide managers with appropriate information for making decisions: (1) A transaction processing system (TPS) is used by supervisory managers to keep track of transactions recorded events having to do with routine business activities-needed to conduct business. A TPS produces detail reports, which contain specific information about routine activities. (2) A management information system (MIS) is used by middle managers. An MIS uses data from a TPS to produce routine reports—summary reports to show totals and trends, exception reports to show out-of-the-ordinary data, periodic reports produced on a regular schedule, and demand reports to produce information in response to an unscheduled demand. (3) A decision support system (DSS) is also used by middle managers. A DSS provides models, mathematical representations of real systems, that gives managers a tool for data analysis and helps them focus on the future. (4) An executive support system (ESS) is used by top managers to support strategic decision making. (5) An office automation system (OAS) is used by all levels of managers as well as non-managers. An OAS combines various technologies, such as word processing, scheduling software, e-mail, and the like, on a network to reduce the manual labor required in operating an efficient office. (6) An expert system helps users solve problems that would otherwise require the assistance of a human expert. (7) Cooperative systems have networks that use groupware to enable cooperative work by groups of people.
- Systems Development: The Six Phases of Systems Analysis & Design. A powerful tool for helping organizations keep up with new information needs is systems analysis and design. In general, a system is a collection of related components that interact to perform a task in order to accomplish a goal. Participants in an information-system project should be users, managers, and technical staff, including systems analysts, information specialists who perform systems analysis, design, and implementation.
Systems analysis and design is a six-phase problem-solving procedure for examining an information system and improving it. The six phases make up the systems development life cycle (SDLC), the step-by-step process that organizations follow during systems analysis and design. The six steps are preliminary investigation followed by systems analysis, design, development, implementation, and maintenance.
(1) The objective of preliminary investigation is to conduct a preliminary analysis, propose alternative solutions, describe costs and benefits, and submit a preliminary plan with recommendations.
(2) The objective of systems analysis is to gather data, analyze the data, and write a report. Several tools are used to analyze the data. Modeling tools enable an analyst to present graphic representations of a system. Data flow diagrams, for example, graphically show the flow of data through a system. CASE (computer-aided software engineering) tools are programs that automate the various activities of the SDLC in several phases. CASE tools may also be used during the analysis phase.
(3) The objective of systems design is to do a preliminary design, which describes the general functional capabilities of a proposed information system; then do a detail design, which describes how the system will deliver the capabilities described in the preliminary design; and then to write a report. Tools used in the preliminary design are CASE (computer-aided software engineering) tools and project management software. Prototyping refers to using workstations, CASE tools, and other software applications to build working models of system components that can be quickly tested and evaluated. A prototype is just such a limited working system developed to test out design concepts.
(4) The objective of systems development is to develop or acquire the software, acquire the hardware, and then test the system. In considering what software to acquire, the systems analyst must make a make-or-buy decision decide whether to create a program or buy existing software.
(5) Systems implementation consists of converting the hardware, software, and files to the new system and training the users. Conversion to the next system may be by direct implementation (stop the old, start the new), parallel implementation (operate both old and new concurrently for a while), phased implementation (phase in new system in stages), or pilot implementation (try out new system by some users).
(6) Systems maintenance adjusts and improves the system by having system audits and periodic evaluations and by making changes based on new conditions.
Source: Using Information Technology: Complete Version, 6/e - Brian K Williams, Stacey C Sawyer