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Technology Terminologies (A to Z)

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A set of wires connecting pieces of computer hardware.

carriage return

The or key on your keyboard. On-line commands often must be followed by .


Compact Disk - Read Only Memory. Optical (CD) disks that are mastered and then can only be read; i.e., the data cannot be manipulated, removed, etc.

cell relay

Packet-switching using small, fixed-sized packets called cells. The fixed size allows for very high speed switching. It is the basis for SMDS and ATM.


Any medium by which information can be transmitted. For example, the air is a channel for our voices just as much as a fiber optic line can be data for a video signal.


Any symbol (usually alphabetic, numeric, or punctuation) that can be entered into your computer.

character set

A set of characters handled by a specified machine; sets include alphabetic characters, numbers, symbols, graphics characters, a space character and control characters. Graphics characters denote a printed mark; control characters produce some particular effect. Two of the most widely used sets are ASCII and EBCDIC.


A tiny piece of semi-conductive material, usually based on silicon, used in the manufacture of electronic components.


A computer program that uses the services of another computer program. Software that extracts information from a server; your auto-dial phone is a client, and the phone company is its server.


A relationship in which client software obtains services from a server on behalf of a person.

Client-Server Interface

An architecture that provides for the splitting of user requests (usually called clients) and a related server function, most commonly across a network. The combined effect is to provide the clients with access to some service such as databases, printing, etc.


n. A language for expressing operations to be performed by a computer.
v. To write in such a language.


The result of two nodes transmitting at the same time on a multiple access network such as Ethernet. Both packets may be lost or partial packets may result.


A vertical arrangement of characters or other expressions.


A request, typed from a terminal or embedded in a file, to perform an operation or to execute a particular program.

communications line

A physical medium (wire, microwave beam) used to transmit data.

communications program

A program that makes a computer act as a terminal to another computer. Communications programs usually provide for file transfer between microcomputers and mainframes.


A program that translates human-readable programs into a form the computer understands. The input (source code) to the compiler is a description of an algorithm in a problem- oriented language; its output (object code) is an equivalent description of the algorithm in a machine-oriented language.


A device or system that is capable of carrying out a sequence of operations in a distinctly and explicitly defined manner. The operations are frequently numeric computations or data manipulations, but also include data input and output. The ability to branch within sequences is its key feature.


A device that brings together at a common center connections to a particular kind of network (such as Ethernet), and implements that network internally.


An electronic meeting place dedicated to a particular subject where users come to participate in discussions or group projects. Conferences can be used to post a variety of information such as news services, newsletters, and statistics; also called "newsgroups," "bulletin boards," or "echoes." An electronic conference provides a many-to-many communication medium, as opposed to the person-to-person nature of e-mail. All conferences have a particular subject or purpose, and the topics and responses they contain might provide items of news, ideas, questions, or other information in almost any form. Some special-purpose conferences may have restricted access, allowing some users to write messages, some only to read, and some neither. The person responsible for the technical maintenance and/or community communication is called the "conference facilitator."


The particular hardware elements and their interaction in a computer system for a particular period of operation.

connect time

Time that elapses while the user of a terminal is connected to a time-sharing system; it is measured by the duration between logon and logoff.

control character

One of 32 characters of the ASCII character set that defines a control function for a character entry and display device such as a terminal. Examples are carriage return, tab, form feed and bell.

control key

A special function key on a computer keyboard, frequently used in combination with alphabetic keys, to enter commands.


A function that reads data from a source, leaving the source data unchanged and writes it elsewhere. One example would be to copy a deck of punched cards onto magnetic tape.


Central Processing Unit. The main internal component of a computer where executions of instructions are carried out and calculations are performed.


A computer system is said to crash when it stops working for some reason and must be restarted.


A symbol on a display screen that indicates the position at which the next character entered will be displayed. The symbol often blinks so that it can be easily noticed.

cursor control

The keyboard keys used to position the cursor on a display screen. They are usually keys labeled with arrows indicating the direction of movement.


The nebulous "place" where humans interact over computer networks (the Internet is considered Cyberspace). Coined by William Gibson in Neuromancer.

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