Computer Glossary

American Standard Code for Information Interchange, an encoding system for converting keyboard characters and instructions into the binary number code that the computer understands.
The capacity of a networked connection, i.e., the more bandwidth you have, the more data you can send along the networked wires. Bandwidth is particularly important for Internet connections, since greater bandwidth also means faster downloads.
binary code
The most basic language a computer understands, it is composed of a series of 0s and 1s. The computer interprets the code to form numbers, letters, punctuation marks, and symbols.
(short for “binary digit”). The smallest piece of computer information, either the number 0 or 1.
To start up a computer.
Software used to navigate the Internet. Netscape Navigator and Microsoft Internet Explorer are today's most popular browsers for accessing the World Wide Web.
A malfunction due to an error in the program or a defect in the equipment.
Most computers use combinations of eight bits, called bytes, to represent one character of data or instructions. For example, the word “cat” has three characters, and it would be represented by three bytes.
Compact Disc Read-Only Memory. Similar to a CD music disc, but designed for computers, a single disc can hold around 640 megabytes of data, enough for several encyclopedias or other reference works. Most software programs are now delivered on CD-ROMs.
A tiny wafer of silicon containing miniature electric circuits that can store millions of bits of information.
A single user of a network application run off a server. A client/server architecture allows many people to use the same data simultaneously; the program's main component (the data) resides on a centralized server, with smaller components (user interface) on each client.
A moving position-indicator displayed on the computer monitor that shows the computer operator where he or she is working.
Slang for the Internet.
A collection of similar information stored in a file, for example, a database of addresses. This information may be created and stored in a database management system (DBMS).
Computer slang for finding and correcting equipment defects or malfunctions in the program.
The option that is presumed to be selected if a user makes no choice. In most programs, the defaults can be changed to reflect personal preferences.
desktop publishing
Use of a personal computer in combination with text, graphics, and page layout programs to produce publication-quality documents.
A list of files stored in the computer.
Two distinct types: the “hard disk” that is inside the computer and stores vast amounts of data (new computers currently come standard with 9–12 gigabyte hard drives); and the “floppy” disk, which is portable, 3.5" square, and can store about 1.4 megabytes of data (the name is a vestige of early 5.25" disks, which were flexible).
disk drive
The equipment that a floppy disk is inserted into so that information may be stored on or retrieved from the disk.
The instruction manual for a piece of hardware or software.
The name of a network or computer linked to the Internet. It is found in an email address after an @ sign. The email address for the First Lady, for example, is, “” being its domain. A domain ends with an abbreviation indicating its type (e.g., “.com” stands for company, “.gov” for government, “.org” for organization, and “.edu” for educational institution).
Used either as a verb or a noun, it refers to the process of transferring information from a web site (or other remote location on a network) to the computer. One can “download a file” or “view a download.”
Disk Operating System. An operating system designed for early IBM-compatible PCs.
Electronic mail; messages, including memos or letters, sent electronically between networked computers that may be across the office or around the world.
A set of data that is stored in the computer.
A structure for containing electronic files. In some operating systems, it is called a “directory.”
Sets of typefaces (or characters) that come in different styles and sizes.
File Transfer Protocol. The format and rules for transferring files from a host to a remote computer.
gigabyte (GB)
One thousand megabytes.
The cause of an unexpected malfunction.
An Internet search tool that allows users to access textual information through a series of menus.
Graphical User Interface. A system that simplifies selecting computer commands by enabling the user to point to symbols or illustrations (called icons) on the computer screen with a mouse.
Software that allows networked individuals to form groups and collaborate on documents, programs, or databases.
A person with technical expertise who enjoys tinkering with computer systems to produce additional features. A hacker is also one who intentionally accesses all or part of a computer or a computer system without authorization to do so (a crime in some states).
hard copy
A paper printout of what you have prepared on the computer.
The physical and mechanical components of a computer system, such as the electronic circuitry, chips, monitor, disks, disk drives, keyboard, modem, and printer.
home page
The main page of a Web site used to greet visitors, provide information about the site, or to direct the viewer to other pages on the site.
Hypertext Markup Language. A standard of text markup conventions used for documents on the World Wide Web. Browsers interpret the codes to give the text structure and formatting (such as bold, blue, or italic).
Hypertext Transfer Protocol. A common system used to request and send HTML documents on the World Wide Web. It is the first portion of all URL addresses on the World Wide Web (e.g.,
Integrates audio, graphics, and/or video through links embedded in the main program.
A system for organizing text through links, as opposed to a menu-driven hierarchy such as Gopher. Most Web pages include hypertext links to other pages at that site, or to other sites on the World Wide Web.
Symbols or illustrations appearing on the computer screen that indicate program files or other computer functions.
Data that goes into a computer device.
The interconnections that allow a device, a program, or a person to interact. Hardware interfaces are the cables that connect the device to its power source and to other devices. Software interfaces allow the program to communicate with other programs (such as the operating system), and user interfaces allow the user to communicate with the program (e.g., via mouse, menu commands, icons, voice commands, etc.).
An international conglomeration of interconnected computer networks. Begun in the late 1960s, it was developed in the 1970s to allow government and university researchers to share information. The Internet is not controlled by any single group or organization. Its original focus was research and communications, but it continues to expand, offering a wide array of resources for business and home users.
An object-oriented programming language designed specifically for programs (particularly multimedia) to be used over the Internet. Java allows programmers to create small programs or applications (“applets”) to enhance Web sites.
kilobyte (K or KB)
Equal to 1,024 bytes.
laptop and notebook
Small, lightweight, portable battery-powered computers that can fit onto your lap. They have a thin, flat, liquid crystal display screen.
Mac OS
Short for Macintosh Operating System. An operating system with a graphical user interface, developed by Apple for Macintosh computers.
megabyte (MB)
Equal to 1,048,576 bytes, usually rounded off to one million bytes.
A computer device or series of devices that store information. Computer memory is measured in terms of the amount of information it can store, commonly in megabytes or gigabytes.
A list of options that users can choose from.
To combine two or more files into a single file.
An abbreviation for Megahertz. One million hertz. One million cycles per second. Unit of measure for band and bandwidth, or for processor speed of a computer CPU, in millions of computer clock cycles per second. For example, the Pentium is currently available in 500 MHz models.
A complete central processing unit (CPU) contained on a single silicon chip.
A device that connects two computers together over a telephone line by converting the computer's data into an audio signal.
A video display terminal.
A small hand-held device, similar to a trackball, used to control the position of the cursor on the video display; movements of the mouse on a desktop correspond to movements of the cursor on the screen.
Software programs that combine text and graphics with sound, video, and animation. A multimedia PC contains the hardware to support these capabilities.
An early operating system developed by Microsoft Corporation.
Computers that are connected to other computers.
An operating system with a graphical user interface, developed by IBM for IBM PCs and compatible computers.
Data that come out of a computer device.
Personal computer.
Pentium chip
Intel's fifth generation of sophisticated high-speed microprocessors. Pentium means “the fifth element.”
personal computer (PC)
A single-user computer containing a central processing unit (CPU) and one or more memory circuits.
Power PC
A competitor of the Pentium chip. It is a new generation of powerful sophisticated microprocessors produced from an Apple-IBM-Motorola alliance.
A mechanical device for printing your computer's output on paper. The three major types of printers are dot matrix, in which individual letters are made up of a series of tiny ink dots formed by punching a ribbon with the ends of tiny wires; ink jet, which sprays tiny droplets of ink particles onto paper; and laser, which uses a beam of light to reproduce the image of each page, before dry toner is applied to the image and transferred to paper. The laser printer is the most popular today. The dot matrix is practically obsolete.
A precise series of instructions written in a computer language that tells the computer what to do and how to do it. Programs are also called “software” or “applications.”
programming language
A series of instructions written by a programmer according to a given set of rules or conventions (“syntax”). High-level programming languages are independent of the device on which the application (or program) will eventually run; low-level languages are specific to each program or platform. Programming language instructions are converted into programs in language specific to a particular machine or operating system (“machine language”) so that the computer can interpret and carry out the instructions. Some common programming languages are BASIC, C, C++, dBASE, FORTRAN, and Perl.
push technology
Internet tool that delivers specific information directly to a user's desktop, eliminating the need to surf for it. PointCast, which delivers news in user-defined categories, is a popular example of this technology.
Random Access Memory. One of two basic types of memory. Portions of programs are stored in RAM when the program is launched so that the program will run faster. Though a PC has a fixed amount of RAM, only portions of it will be accessed by the computer at any given time.
Read-Only Memory. One of two basic types of memory. ROM contains only permanent information put there by the manufacturer; information in ROM cannot be altered, nor can the memory be dynamically allocated by the computer or its operator.
An electronic device that uses light-sensing equipment to scan paper images such as text, photos, and illustrations and translate the images into signals that the computer can then store, modify, or distribute.
search engine
Software that makes it possible to look for and retrieve material on the Internet, particularly the Web. Some popular search engines are Alta Vista, Yahoo!, Web Crawler, and Lycos.
A computer that shares its resources and information with other computers, called clients, on a network.
Computer programs; also called “applications.”
Software that allows one to calculate numbers in a format that is similar to pages in a conventional ledger.
Exploring the Internet.
Input device that controls the position of the cursor on the screen; the unit is mounted near the keyboard, and movement is controlled by moving a ball.
Uniform Resource Locator. The protocol for identifying a document on the Web; the Web address (e.g.,
A large unmoderated and unedited bulletin board on the Internet that offers thousands of forums, called newsgroups. These range from newsgroups exchanging information on scientific advances to celebrity fan clubs.
user friendly
A program or device whose use is intuitive to people with a nontechnical background.
virtual reality (VR)
A technology that allows you to experience and interact with images in a simulated three-dimensional environment. For example, you could design a room in a house on your computer and actually feel that you are walking around in it even though it was never built. (The holodeck in the science-fiction TV series Star Trek: Voyager would be the ultimate virtual reality.) Current technology requires the user to wear a special helmet, viewing goggles, gloves, and other equipment that is wired to the computer.
An unauthorized piece of computer code attached to a computer program or portions of a computer system that secretly spreads from one computer to another by shared disks and over telephone lines.
A portion of a computer display used in a graphical interface that enables users to select commands by pointing to illustrations or symbols with a mouse. “Windows” is also the name Microsoft adopted for its popular operating system..
World Wide Web (“WWW” or “the Web”)
A network of servers on the Internet that use hypertext-linked databases and files. It was developed in 1989 by Tim Berners-Lee, a British computer scientist, and is now the primary platform of the Internet. The feature that distinguishes the Web from other Internet applications is its ability to display graphics in addition to text.
word processor
A computer system or program for setting, editing, revising, correcting, storing, and printing text.