Glossary of computer terms

This isn't an exhaustive glossary, just a few of the most common terms you may come up against when buying digital products. An enormous glossary can be found at Computer Hope, or there's an endless supply of information on Wikipedia.

AAC (Advanced Audio Coding)

AAC is a digital audio encoding format with better quality than MP3 format. AAC is the default format used by Apple's iTunes store.

Access Point

A point of wireless access to a network. Devices connected to an access point can communicate with each other, or to the Internet if there is a link to it in the network.

Active matrix

Active matrix technology is used in high-quality flat-panel displays, created by placing diodes, or small semiconductors, over a grid of wires. When a current passes through the diodes, they light up in different colors, depending on the strength of the current.


A Microsoft technology that was built to link desktop applications to the World Wide Web - commonly it allows small programs to run inside your browser.

ADC (Analog-to-Digital Converter)

An analog-to-digital converter (ADC, A/D or A to D) is a device that digitizes analogue content into a binary format that the computer can understand, for example when transferring VHS video to a digital format.


A piece of software which enhances another software application. A common add-on is a browser extension, which modifies the interface and/or behavior of web browsers.

ADF (Automatic Document Feeder)

An ADF is used in photocopiers and scanners to automatically feed pages into the machine, allowing multiple pages to be copied or scanned without the need to place each individual page.

ADSL (Asymmetric Digital Subscriber Line)

ADSL is a broadband technology used for connecting to the Internet and transferring data over telephone lines.


Adware (advertising-supported software) is any software package which includes advertisements, often in the form of a pop-up window. The object of the Adware is to generate revenue for its author. Adware, by itself, is harmless - however, some adware may come with spyware such as keyloggers and other privacy-invasive software.

AIFF (Audio Interchange File Format)

AIFF is an audio format developed by Apple for storing high-quality audio data. AIFF files are similar to Windows WAVE files in size and quality, and both can hold CD quality audio and can be burned onto an audio CD. AIFFs can be read by Mac and PC computers.


Analogue data is a continuous stream of information to the senses, whereas digital information is a series of discrete values - in computing this equates to ones and zeros.

A turntable is an analogue device, as it reads the grooves from a record as a continuous signal, whereas a CD player is digital, as it reads a series of ones and zeros from a disc.


Android is a mobile operating system developed by Google, and is used by several smartphones and tablet computers.

Animated GIF

A GIF (Graphics Interchange Format) is a type of image file, which can either be a still picture or an animation.

Anti-virus software

Security software that helps protect computers from online viruses, adware, spyware and other malware.

API (Application Programming Interface)

An API is a set of commands, functions, and protocols which programmers use when building software for a specific system. The API allows programmers to use predefined functions to interact with the system. The term API may be used to refer to a complete interface, a single function, or a set of APIs.


App is short for application, but more recently refers particularly to Mobile Applications - software applications designed to run on smartphones, tablet computers and other mobile devices.



Apple is an American company that makes Macintosh computers (e.g. iMac, Mac mini and Mac Pro desktops, and MacBook Air and MacBook Pro laptops), as well as personal electronic devices such as the iPod, iPhone, and iPad. They also develop software, including the Mac OS operating system, iLife, iWork, iTunes, and pro media applications such as Aperture, Logic and Final Cut.


A software program that runs on a computer or other digital device, designed to help the user to perform specific tasks. Examples of applications include web browsers, e-mail programs, word processors, games and utilities.


As in real life, a digtal archive is a place where old information is stored. For example, a web archive is a website, or part of a website, where old news, articles, stories etc are listed. On a computer, old folders & files can be archived by using software which compresses the archive into a single, smaller file.

ASCII (American Standard Code for Information Interchange)

ASCII is the universal character-encoding scheme used to represent all upper and lower-case letters, numbers, and punctuation in computers, communications equipment, and other devices that use text.


ASP.NET is a web application framework developed by Microsoft to allow programmers to build dynamic web sites, applications and services. It superceded ASP (Active Server Pages).


A file which has been sent with an email. This could be an image, a video or any other document. It is important not to open email attachments unless you're sure of the sender's identity and reason for sending, as malicious attachments can contain viruses or other malware.


An autoresponder is a program or script on a mail server that can be set up to automatically reply to e-mails.


An avatar is an online character representing a real person in games, message boards or social networking services, in either a three-dimensional form, as in games or virtual worlds, or a two-dimensional form as an icon in Internet forums and other online communities.