Computing terms explained in plain English
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Super Audio CD. A high-resolution audio CD format.
A way of starting Windows so that various programs and peripherals are prevented from working. This is useful to help diagnose the cause of problems if a computer is behaving oddly.
A recording of instruments or sounds. Samples can be used with a sequencer to make music, or downloaded to a wavetable sound card so it can reproduce those sounds, combining them and playing them back at different pitches to make music.
A piece of hardware or a software program for playing – and sometimes editing – samples.
A typeface without the ornate details called serifs, such as Arial or Helvetica.
Serial ATA. An interface for connecting modern hard disks and optical discs to a computer.
Speaker designed to reproduce mid- and high-range audio frequencies.
Navigation system that uses satellites to establish the position of a receiver and its user while in motion.
To change the dimensions of a picture, keeping it in proportion to its original size.
A disk-checking utility incorporated into Windows that can detect and repair minor problems with your disk drives.
A device that uses a light sensor to convert a drawing, photo or document into a digital file for archiving, editing or sharing online.
A standard connector for video and audio signals.
In spreadsheets, a named set of input values you can substitute in a worksheet.
Also screenshot. An image of what was displayed on screen at a particular moment. A screen is captured to the clipboard in Windows by pressing the Print Screen key. You can then copy it to a graphics file or simply print it off.
A software application that attempts to identify and interpret what is being displayed on the screen, including text and descriptions of images, menu bars and the content of websites. Windows 7 and Vista come with screen-reading software.
The number of pixels displayed on the screen, measured horizontally and vertically, that make up the image. The more pixels, the higher the resolution and the sharper the picture.
A program that runs on a computer after a short period of inactivity and displays a moving image on screen. Originally intended to prevent damage to monitors caused by displaying the same image for long periods, many screensavers now incorporate passwords to protect your work from prying eyes.
An image of what was displayed on screen at a particular moment. A screen is captured to the Clipboard in Windows by pressing the Print Screen key. You can then copy it to a graphics file.
A short program that is stored on a web server to control part of a website. For example, a script could check that a date you have entered is valid, or move words across the screen.
When a document, an image or a list of items is too long to display in a window you can scroll up or down by clicking on the window's scroll bar (also called the vertical scroll bar).
The section of a window – normally grey with a slider control – you must use to scroll around when the window's contents are too large to display at once.
Small Computer System Interface (pronounced 'skuzzy'). A connection between such things as disk drives and scanners, and a PC.
Secure Digital card. A popular type of memory card.
High Capacity SD memory cards, which can store more than 4GB of data.
Synchronous Dynamic Ram. The type of memory in most modern PCs. It is significantly cheaper than its biggest rival, RD-Ram.
A site on the internet that indexes the names and addresses of other sites. It enables you to search for sites containing certain key words. Google is a search engine.
Customising web pages so they appear prominently in online search results.
The text given to a search engine that forms your search on the internet. It can be one or several keywords, use special codes, or even be a natural question.
An address used by hard disks to find information, also used in calculating the total amount of space available.
A piece of data sent from one computer to another designed to prove the authenticity or security of information on the internet.
A series of letters or numbers – or a phrase – that you have to type in to access a wireless network. Allows people to stop others using their wireless networks without permission.
In graphics and page layout programs, the icon for this often looks like the dotted outline of a square. This tool allows you to select items by drawing a square or rectangular shape around them. Once selected, you can manipulate them all at once.
The part of the camera that captures each image. Analogous to a piece of film on a film camera.
Program used to arrange and mix music recorded using samples, software synthesisers, as well as real instruments such as guitars and vocals.
A camera setting that will automatically take a series of photographs at set intervals. It is particularly useful for action shots or for time-lapse photography.
A cable that connects to a serial or Com port. Such leads can connect peripherals to the computer or can be used to link one computer to another.
A socket on the back of a PC used to connect serial devices, also known as a Com port. Often used on a PC to connect an external scanner. Largely superseded by USB sockets.
A design of typeface that incorporates decorative 'tails' or serifs on many letters.
A computer on a network, such as the internet, that distributes information to other PCs.
A large download that contains lots of fixes and updates for Windows or other programs.
A function that runs as part of Windows, without needing a separate program, and can be turned on or off, such as file sharing.
A DVD or CD can be created in several sessions – each time more data can be added but previous data cannot be deleted. Some older computers and CD players have trouble reading 'multi-session' discs created in this way.
A device that enables a TV set to receive digital TV broadcasts.
Programs that you can try out free before deciding whether to buy them. Usually much cheaper than conventional software, shareware programs are normally written by individuals and distributed over the internet.
A part of most printers and some scanners. It holds a number of sheets of paper and feeds them into the mechanism automatically, one by one.
Technology developed by Macromedia that allows web pages to contain interactive multimedia. Typical uses include animations and games.
A file that acts as a link to something else, such as a program file or disk drive.
The delay on a digital camera between pressing the shutter button and a picture being taken.
A feature of Windows 7 and Vista that sits on the side of the desktop and can contain tools such as a clock, photo viewer, and updates from web pages and services.
Simulation. Used when referring to the simulation game genre.
Subscriber Identity Module. The smart card used by all digital mobile phones. The SIM card carries the user’s identity and phone number for accessing the network.
Single In-line Memory Module. A 'stick' of Ram, used in 486 and Pentium-based machines. Virtually all modern PCs use Dimms, Dual In-line Memory Modules.
Games that simulate real life, with the most popular being flight simulators.
Simultaneous broadcast. A programme or event broadcast over more than one medium or platform.
A single-pass scanner captures the image in one movement of the scanhead over the picture. Multi-pass scanners must make one pass for each colour channel to be scanned.
Session Initiation Protocol. A standard for setting up calls between internet telephony devices.
A different, purely cosmetic appearance for an application.
A control that enables you to change a setting by clicking and 'dragging' a slider switch.
A collection of pages arranged in sequence that contain text and images for presentation purposes.
Single-Lens Reflex. A type of camera in which the same lens is used for viewing subjects in the viewfinder and for taking pictures.
A credit card with an embedded microchip for storing personal identification data.
A form of solid-state storage used by some digital cameras and MP3 players. Data files, normally photos or music, are stored on small removable cards. These are about the same size as Compact Flash cards, but physically more flexible, being less than 1mm thick.
A modern phone with computer functions on which users can install their own programs.
A face created using text characters, such as :-) or ;-).
A technology applied to fonts to make them look smoother on screen at small and large sizes.
Short Message Service. More commonly called text messaging.
Simple Mail Transfer Protocol. A standard for sending email messages. SMTP is now largely reserved for sending messages rather than receiving them.
In graphics applications, the Smudge tool helps to smooth out any joins between image areas. It is particularly useful where part of your picture has been cloned but you can see where you've painted over a scratch because sometimes cloning isn't subtle enough.
Websites that enable you to chat, share news and photos with friends. Facebook is an example of a social network.
Connector on your PC's motherboard for Pentium processors or equivalent non-Intel chips.
Any program or group of programs that tells hardware how it should perform, including operating systems such as Windows, word processors, DTP applications and games.
A device, such as an MP3 player or memory card, which has no internal moving parts.
Sound card made by Creative. The Soundblaster was one of the first de facto PC audio standards, and many cards emulate it so they can be used with the hundreds of games that support it.
An expansion card that lets a PC create game sound effects, music, and so on. Almost all PCs have a sound card built in as standard but more powerful sound cards can be bought and fitted.
Junk email sent to large groups of people offering such things as money-spinning ideas, holidays, and so on. Named after the Monty Python Spam sketch.
Software that roams the internet looking for email addresses to which commercial offers can be sent.
A person who sends junk emails.
Sony/Philips Digital Interface. A standard for transferring digital audio information between devices. S/PDIF sockets can be both optical and electrical, and found on such things as sound cards and DVD players.
Analysing the spoken word via special software so that a PC can recognise it and translate spoken commands into computer actions.
A tool found in text editors that checks for, and in some cases corrects, misspelt words.
A selection type in dialogue boxes, where adjustments are made by clicking on up- and down-pointing arrows.
Conveys an impression of what a document will look like. Also refers to the screen you see when an application begins to load.
Temporarily transferring data to the hard disk or to some other temporary storage place, before passing it on to its final destination. Most often seen in printing, where the PC spools data to the hard disk to finalise it before passing it to the printer.
A software application for creating sheets of calculations, set out in rows and columns. They may be used for accounting, budgeting, and any other sort of financial or mathematical calculation. Better spreadsheet programs also have graphical abilities, allowing charts and graphs to be plotted. Leading programs include Microsoft Excel and Open Office Calc.
Software installed (usually surreptitiously) to monitor and report back on a computer's use. Spyware can also be used to record keyboard strokes and change settings.
Solid-state drive. Storage that, unlike a hard disk, uses no moving parts. Faster but more expensive than conventional hard disks.
Service Set Identifier. A name used to identify a wireless network.
Secure Sockets Layer. A technology for keeping information secure and secret when sent over the internet.
Also known as the Score or Notation editor, this displays notes using the traditional 'dots on wires' familiar to classically trained musicians.
The button on the far left of the Taskbar in Windows. Click on it to access all the programs installed on your computer, as well as printers, and the Control Panel. Paradoxically, you should also click it to shut down your PC.
The page that appears when you first start your web browsing program. Also known as the home page, it is user-selectable.
A Windows tool that enables the user to press a key, such as Shift, and have it remain active. Designed to assist people who find it difficult to hold down two keys at once.
A series of sketches that symbolise specific scenes from a film or video project, used to help map out ideas in advance.
A genre of game involving multiple characters or elements, with multiple goals, such as a war game where you must win battles using troops, tanks and aircraft.
Audio or video material that can be played as it is downloaded from the internet or transferred from another computer. Broadcasts over the internet are often streamed so that you don't have to download a whole file before you start listening or watching. Streaming media sometimes stalls if the source material is received slower than it is played back.
In graphics programs, the visible attributes applied to a path, such as weight (thickness), colour, style and so on.
A collection of settings that can be applied to text in a word processor, such as size, font, bold or italic. Changing the settings for a style changes all the text with that style applied.
A plastic pointer styled like a pen, used for operating some touch-sensitive screens.
Substitute user. A Unix command that changes your permissions temporarily to those of another user, usually the 'root' administrator.
Smaller than a headline, but larger than ordinary text, sub-heads break up long stretches of text and help readers navigate round more easily.
Short for subnetwork, which can describe any group of computers that form part of a larger network.
A special type of speaker designed to reproduce deep bass sounds only. Even on a stereo system, only one subwoofer is required because human ears cannot detect the direction of bass frequencies.
Popular metaphor used for describing someone exploring the world wide web.
Cinema-like sound that uses multiple speakers.
Super Video Compact Disc. A video disc type that squeezes a small amount of DVD-quality video onto a standard CD.
Scalable vector graphics. A file format that enables images to be expanded without loss of details.
Super-VHS. A good-quality high-band video standard used by camcorders.
Super-VHS-C. A good-quality high-band video standard used by camcorders, but using a smaller cassette than standard S-VHS.
A high-quality video connection that carries brightness and colour information separately.
An area of hard disk space that your PC can use as 'virtual' memory, or Ram. This allows you to have more programs open at once but will be slower than having an equivalent amount of real Ram.
Allows more than one PC to be connected to a wired network.
Also known as CD synchronisation. Automatically starts and stops a tape or disc when recording a CD.
The date used by the Dos and Windows operating systems. Programs that need to know the date should ask Dos or Windows for the system date, not look directly at the clock.
The files that run when the computer starts up, usually containing essential instructions to make installed hardware and software run properly. The autoexec.bat and config.sys files are system files.
The software that creates and restores Restore Points – records of settings at a specific time to which Windows can revert if a problem occurs.
This folder can be found by clicking the Windows Start button, then looking within Programs/Accessories. In it you will find a number of utilities useful for maintaining and troubleshooting your copy of Windows.
Located in the taskbar of Windows 95, 98 and ME (usually at the bottom next to the clock) and contains miniature icons for easy access to functions. In later versions it is called the Notification Area.
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