Computer Glossary

Glossary

404 error

An error message received when you try to access a web page that either doesn't exist or is unavailable at the address you gave.

ActiveX

A Windows technology which allows programmers to do various things on your computer. The early versions had security issues which hackers could exploit.

ADSL

(Asymmetric Digital Subscriber Line) A method of connecting a computer to the internet over a standard voice phone line using ethernet office networking technology. Most broadband connections work this way. Asymmetric because it is faster from internet to PC than the other way.

Adware

Software which displays advertisements on your computer. Sometimes installed as part of a "free" application, sometimes by stealth. See also Malware, Spyware.

AGP

(Advanced Graphics Port) A special slot on the PC motherboard for graphics cards, and the format of the cards themselves. Standard on new PCs from 1998. "AGP x 2" runs at twice the speed of the original AGP, AGP x 4 at four times the speed etc. Now being replaced by PCI Express.

AI

(Artificial Intelligence) A program designed to respond "intelligently" to various situations, for example the computer opponent(s) in a game.

Android

A popular operating system for smartphones and tablets, owned by Google.

antivirus

Software which protects computers from viruses and suchlike. Has to be updated frequently to keep up with the latest threats, so is usually sold with a subscription which enables you to download updates from the internet.

Apple

The Apple Corporation makes the only successful mass-market personal computer which doesn't use Microsoft Windows, the Mac, and the phenomenally successful iPhone (smartphone), iPod (music player) and iPad (tablet).

App

(APPlication) Any software used to carry out a particular task, such as office programs or games, particularly on smartphones. Usually downloaded to the device from an online store. Essentially another word for program.

Applet

A small program used to carry out a particular task, often on a web page.

Architecture

The basic design of a computer's hardware. Computers with different architecture, such as the PC and the Mac, cannot run each others' programs.

Attachment

A file sent by email is "attached" to the email. An attachment can be a picture, a document, a program or any other type of file. You should never open an attachment if you are not sure what it is, because some viruses propagate as email attachments; but they can't infect your machine if you don't open the attachment.

autocorrect

A feature in many programs which automatically corrects your spelling, and even your grammar, as you type. Better switched off if you use obscure technical terms, or prefer your own interpretation of the rules of grammar, or else you are likely to find that it's "corrected" your text to something you didn't intend.

Avatar

A picture or figure representing a person in an online environment.

Backup, back up

A backup is an extra copy of your work, eg documents, pictures etc, saved onto a removable storage medium such as CD, DVD or magnetic tape, so that if your computer is stolen or breaks down you don't lose everything. Backup is a noun, back up is a verb.

Backwards-compatible

A program (or system) designed to work with data generated by earlier versions of itself, even though the format may since have changed completely.

Bandwidth:

A measure of total amount of data transferred over a period of time, often used to measure how busy a website is. A webhost will usually base its charges on the bandwidth a website uses, ie how much data per month is requested from it.

Biometric

A system that examines biological things like fingerprints or retinas, usually for security purposes.

BIOS

(Basic Input/Output System; pr. "by-oss") A program built into every PC for setting up very basic things, like how many hard and floppy disks you have and what type they are; the first thing that loads when you start your PC. You usually only need to access the BIOS if you are upgrading your hardware, eg adding more RAM or an extra disk drive, or setting a power-on password. BIOS settings are stored in a special type of memory called CMOS.

Bit

The smallest unit of information in a computer, can either equal 0 or 1. Eight bits equal one byte.

Bluetooth

A short range wireless data communication system for smartphones and other computing devices. However Bluetooth devices from different manufacturers wouldn't always communicate with each other reliably, so it hasn't really taken off as the industry had hoped, and it is now under threat from faster wireless technologies (see Wi-Fi).

Bmp

(BitMaP) A standard type of graphics file. An uncompressed format, so the files tend to be fairly big.

Boot, boot up

Usually used to mean "start up the computer". Literally, the process of loading up the operating system and getting the computer ready for use. See Reboot. A "boot password" is a password you have to give to start up the computer.

Boot disk

A CD pr DVD which holds a copy of the operating system, or enough of it to start the computer, useful if the computer won't start up properly from the hard disk.

Bps

(Bits Per Second) A measure of how quickly information is being transferred, usually via a modem or network. Divide by ten to get an approximation of the number of characters per second (cps). See also Kbps, Mbps.

Broadband

Internet access over a connection much faster than an ordinary modem, such as ADSL or cable.

Browser

A program used for viewing World Wide Web pages on the Internet. Usually available free for download. Popular browsers include Internet Explorer (IE), which is built in to Windows, Mozilla Firefox, and Google Chrome. The most popular browser on Apple devices is Safari.

Buffer

A temporary storage area for data, often used to "smooth out" incoming audio or video streams. Several seconds worth of material is stored in the buffer and it is then played back from there, so that if there is a brief interruption in the stream your music or video doesn't stop.

Bug

Error, especially in a program, that has been missed in testing. The story goes that the original bug was an insect that got itself cremated inside an electrical circuit in an early computer, causing it to fail (and I don't suppose the insect enjoyed it much, either). It took them ages to figure out what was causing the problem, and when they eventually found the bug the story passed into legend.

Burn

Create a CD or DVD.

Byte

A basic unit of measurement for pieces of information; the space required to store one character. See also Bit, Kilobyte, Megabyte, Gigabyte, Terabyte.

Cache

A temporary storage area for frequently or recently used data, either in memory, on your hard disk or the internet. For example, if you go back to a webpage you have recently visited, your PC will usually be able to display it from the internet cache on your hard disk, so it won't need to download it from the internet again.

CAD

(Computer Aided Design) Software used to produce complex technical drawings by designers and engineers.

CD Burner

A CD drive that can create ("burn") CDs.

CD-ROM, CD-R

(Compact Disk-Read Only Memory) A misnomer, as strictly speaking it is not memory but storage. Identical to standard music CDs. A popular medium for releasing programs. Now being replaced by DVD, which has a much higher capacity.

CD-RW

(Compact Disk-ReWriter) A CD drive which can create CDs, either audio or data, using special rewriteable CDs which are also often called CD-RWs. A CD-RW drive can also create ordinary CDs, though not rewrite them.

Character

A letter of the alphabet, number, space or punctuation mark is a character.

Chatroom

A website where you can meet and chat live (via the keyboard) with other internet users. Most such websites have multiple "rooms", each dedicated to a particular topic or theme.

Chip

A silicon wafer with millions of tiny circuits engraved on it - what computers are made of..

Clipboard

A temporary storage area in Windows. When you cut (Ctrl-X) or copy (Ctrl-C) highlighted text, documents or whatever in Windows they are sent to the clipboard; when you paste (Ctrl-V) they are copied from the clipboard to the cursor position. Sending something to the clipboard automatically overwrites its previous contents.

Cloud, the

Remote storage via the internet, or sometimes just the internet in general. Called "the cloud" because you don't know where your data is physically located, it's just out there somewhere.

Cluster

Data stored on a disk is spread across a number of clusters, small physical areas on the disk. How big they are depends on the way the disk is formatted.

CMOS

(Complementary Metal Oxide Semiconductor; pr. "see-moss") A special type of memory which retains its data when the PC is switched off, used to store settings for things like what type of hard disk you have, and how much memory. The settings are accessed via the BIOS.

Codec

(COmpressor/DECompressor) A small piece of computer code that tells the computer how to decode particular types of information, usually video files. If your video player won't play a particular format, you can usually download and install a codec which will tell it how from the internet.

Compatible

Compatible pieces of equipment can work together; incompatible ones can't.

Compression

A way of making files smaller, either to fit into restricted storage space or to speed up transmission over the Internet. Popular compression standards include JPEG and GIF for pictures, MP3 for music files, MPEG, MP4, AVI and MOV for movie footage, and zip for just about everything else.

Cookie

A small data file stored on your computer by a website, in theory to allow it to "remember" your preferences, but in practise mostly used to track which adverts you have seen. You can set most browsers to reject all cookies, or to ask your permission before storing them, but this can generate multiple error messages on some websites and is generally more hassle than it's worth - they are pretty harmless.

CPU

(Central Processing Unit) The nerve centre of the computer : everything flows through it. Often just called "the processor". The best known PC processors are Intel's Pentium and AMD's Athlon.

Crack, cracked

A crack is a small program intended to defeat software's copy protection, thus allowing unlicensed copies to be made - stealing it, in effect. Software that is distributed with its copy protection disabled or bypassed has been "cracked".

Crash

When a computer program or operating system stops working completely or almost completely it (or the computer) is said to have "crashed". When a computer crashes it usually needs to be rebooted before it can be used again. See also lockup.

CRT

(Cathode Ray Tube) The imaging technology used in older desktop monitors. Provides an excellent colour display, but is extremely bulky and is widely being replaced by flatscreens.

Cyberspace

Loosely speaking, the internet, and virtual places thereon. Cyber is used as a prefix meaning related to computers or the internet.

Cybersquatter

Someone who buys up internet domain names in order to sell them on at a profit.

Data

Any information created by a user, such as documents, pictures or sound recordings.

Database

A program used for organising any kind of information on a computer into a searchable form, anything from a list of contacts to a complex stock control and accounts system.

DDR

(Double Data Rate) A fast type of RAM for a PC. DDR2 is a yet faster version.

Default

A default setting is one you haven't changed - what a program will do (or use) if you don’t tell it any different. "Accept the defaults" means leave any settings as they are.

Desktop

A computer designed to sit on a desk (as opposed to a laptop). In Windows, it also means the screen you see when you aren't running any programs, with "My Computer", the Recycle Bin and so on.

Digital

Literally "to do with numbers". Often used to describe a device using computer technology to replace older, traditional technologies. For example, a digital camera is one that stores images electronically rather than on chemical film.

DIMM

(Dual In-line Memory Module; pr. "dim") A module of RAM (memory) for a PC, replacing the older SIMM specification.

Disk

Generic term for a type of storage device, such as a hard disk or a floppy disk (diskette). So called because the important part, where the information is actually stored, is circular, although you can't see it because it is hidden away inside a protective shell.

DNS

(Domain Name Service/System) An internet service that converts a human web address such as www.jonstorm.com into the numeric address that computers use, called the IP address. "Can't resolve DNS" usually means that this conversion has failed and therefore the website can't be found.

Dongle

A small hardware device used for copy protection with some software. The dongle must be plugged in to a port on the computer, often the printer port, or the software won't function. They are unpopular with users because if the dongle gets lost or broken, the software won't function.

DOS

(Disk Operating System; pr. "doss") Usually refers to MS-DOS, which was the standard operating system for PCs until Windows 95 came out, now pretty much obsolete. Controlled by typing in text commands and has several serious limitations, but requires a much less powerful computer than Windows 95.

Download

To transfer information (files) from a network (such as the Internet) onto a user's PC. See also upload.

Dpi

(Dots Per Inch) A measure of picture quality, often used to measure printer capabilities. The higher the number, the better the quality.

Driver

A small program used by the operating system to control hardware such as a sound or video card. Often downloading the latest driver for a device from the manufacturer's website will improve its functionality.

Dual core

PC processors which have two complete processors on the same chip, allowing computers to handle multiple tasks faster. See also quad-core.

Dual layer

A technology allowing two layers of data to be written to a DVD instead of the usual one, thus increasing its capacity.

DVI

(Direct Video Interface) A special type of connector for computer monitors, particularly flat panels.

Email

(Electronic mail ; pr. "ee-mail") A way to send messages between computers, or more to the point their users, either over a network or the Internet. E-mail is usually just text, but can have pictures or other files attached. See Attachment.

Encrypt

Coding data so that it can't be read by hackers etc when transmitted over the internet. For example, any reputable website selling goods by credit card will encrypt your credit card number and personal details.

Ethernet

The system used to connect computers to a network or the internet with a physical cable, including most broadband internet connections. Usually much faster than a wireless connection.

Exe

(EXEcutable; pr. "exie", "dot exie" ) A file which is usually the main part of a program. A program may consist of just an exe file and nothing else, or there may be dozens of files, including more exes.

Expansion card

A circuitboard which can be plugged in to an expansion slot on the PC's motherboard, to give the PC extra capabilities. A lot of the features originally provided by expansion cards, like sound, graphics and network connections, are now built in.

File

All information on a computer is stored in files, whether it is part of a program, a document created by a user, a picture, or anything else. Most software is made up of dozens, sometimes hundreds, of different files

Firewall

Originally a dedicated computer between you and the internet, preventing hackers, spammers and similar undesirables from taking over your PC. Now often just a program running on your PC, performing the same task. Recent versions of Windows have one built-in.

Firewire

A standard for very fast data transfer, popular for applications that use very large files, particularly video editing. Requires special hardware, generally added to a computer as an expansion card.

Flash

A technology for displaying animations (mostly) on webpages, created by the Macromedia Corporation. The Flash Player is a plugin which enables internet browsers to display the animations.

Flash drive

A removable data storage device, usually thumb sized and plugged into a PC's USB port.

Gigabyte (or Gig)

Unit of measurement for pieces of information : approximately 1 billion bytes, 1 million kilobytes, or 1000 megabytes. Hard disk sizes are usually measured in gigabytes. Often shortened to "GB", "Gig" or just G.

Graphics

A catch-all term for anything involving drawing images on a PC screen. A game with great graphics is one that is visually spectacular.

Hard disk

A computer's main (and fastest and most convenient) storage for programs and data. Originally named to distinguish it from floppy disks. All PCs are fitted with hard disks, sometimes more than one. The first (or only) hard disk is usually called C: by the computer. The most popular hard disk formats are currently EIDE and SCSI.

Hardware

The physical parts of a computer.

HD, HDD

(Hard Disk Drive) The main data storage unit in a computer. See hard disk.

Homepage

A page on the World Wide Web. Confusingly "homepage" is used indiscriminately to describe several slightly different things : an amateur's hobby site; the front or main page of any website; or the page which your browser first goes to when you start it up.

Hotspot

A location where a computer can connect to a wireless network (see Wi-Fi).

HTML

(HyperText Markup Language) The system used for creating World Wide Web pages, ordinary text with commands for special effects like pictures, colour and links enclosed between < > symbols. You can add the various HTML commands to ordinary text by hand - it's not difficult, see Absolute Beginner's HTML - or have it generated for you by software, either one of the many specialist editors or even a word processing program like Microsoft Word (although Word isn't very good at it).

Hyperlink

Any kind of link on a webpage. Unless you typed this page's URL in by hand, you got here by clicking on a hyperlink.

IBM

(International Business Machines) The company that designed and built the first PCs, and still a giant of the industry. Standard PCs were originally referred to as "IBM compatible", although IBM no longer controls the PC standard.

Icon

Small pictogram either representing a file, or providing shortcuts for carrying out common tasks such as saving and printing inside an application.

IDE

(Integrated Drive Electronics ) A type of PC hard disk, now obsolete, the foreunner of EIDE.

IM

(Instant Messenging) A program that allows you to "chat" live via keyboard over the internet. Both parties must be running the same IM software - there are several different brands, mostly incompatible with each other.

Inkjet

A very popular colour printer technology, which works by squirting tiny jets of ink onto paper with great precision.

Intel

The Intel Corporation is the leading manufacturer of processor chips for PCs, most famously the Pentium.

IP address

(Internet Protocol address) A unique number assigned to any computer connected to the internet, including yours, in the format 255.255.255.255. Each of the four blocks of numbers can be any value from 0 to 255. They can either be assigned permanently ("static IP") or per session ("dynamic IP"). Most ISPs assign them dynamically, ie when you connect to the internet.

ISP

(Internet Service Provider) A company which provides a connection to the internet, or internet services.

IT

(Information Technology) What computers are all about - using technology to manage information. The computer industry is often called the IT industry, and computer departments often refer to themselves as the IT department.

Java

A programming language used to create small programs called applets, often to produce special effects on web pages.

JPEG, jpg

(Joint Picture [Experts] Group; pr. "jay-peg") A standard type of compressed graphics file, widely used on the WWW. Particularly good for photographs. See also compression.

LAN

(Local Area Network; pr."lan") A network of computers connected together, usually in a single department or building. See also WAN.

LCD

(Liquid Crystal Display) A type of computer screen, originally used only on laptops but now increasingly used for desktop PCs and even televisions.

Linux

A rival PC operating system to Microsoft Windows, but unlike Windows it is "open source", which means that anyone can create their own version of it without having to pay royalties, and requires a much less powerful computer. Initially required a lot of technical knowledge, but is rapidly being made much more user-friendly.

Mac, Macintosh

The Apple Corporation's alternative to the PC, much loved by its devotees but completely incompatible with PCs, though some popular software is also released in Mac format.

Mac address

The unique serial number of an Ethernet card, required for connecting a PC to a network. (Nothing to do with Apple Macs, despite the name).

Malware

A catch-all term for software installed by stealth onto a PC for malevolent purposes (hence the name). These may include displaying unwanted ads (adware), installing software you didn't ask for, or spying on your activities (spyware) and reporting them back to the culprit so that he can steal your bank account, address book etc.

Megapixel

A million pixels. Often used to measure the quality of digital cameras : the higher the number the better the camera.

Memory

Also known as RAM. Where the computer holds whatever you are currently working on. The contents of memory are lost when the computer is switched off.

Modem

(MOdulator/DEModulator) A device for allowing computers to communicate over a phone line.

Monitor

The screen of a PC.

Motherboard

The main circuitboard in the computer - all the other bits and pieces are plugged into it.

Network

A way of linking several computers together so that their users can share resources such as printers and documents, often via a central computer called a server. See also LAN, WAN, Ethernet.

OEM

(Original Equipment Manufacturer) A company that actually builds computers, as opposed to just retailing them. "OEM software" is ordinary software bought in bulk at a discount by the OEM and pre-installed on a new machines, usually without printed manuals. OEM software cannot legally be sold separately from a computer, so when offered for sale at huge discounts is either pirated, or not what it claims to be.

Operating System

Every computer has an operating system, which is a sort of master program that runs automatically when you switch the computer on, and continues running till you switch off. It is responsible for the many routine tasks required to keep a computer running : moving the pointer when you move the mouse, providing icons and menus, running other programs such as a word processor or a game which you may request, controlling the various disk drives, the screen and so on. The most widely used PC operating system is Microsoft Windows.

PC

(Personal Computer) Originally just short for "personal computer", PC is now an industry standard, partly evolved in the marketplace, partly agreed by a committee of the major players in the computer industry.

PCI

(Peripheral Component Interconnect) A standard for PC expansion cards, currently the most popular in desktop PCs. A "PCI slot" is a socket on the motherboard for such cards.

PCI Express

A special type of PCI slot for graphics cards, replacing AGP in most new computers.

Peer-to-peer

A type of network where computers are connected together directly, rather than via a server, allowing them to access each other's hard disk etc. Most home networs work like this.

Pentium

The best known PC processor (or CPU), manufactured by Intel.

Peripheral

Anything that plugs into the computer, such as keyboard, printer etc.

Phishing

An internet scam in which a forged message from a bank provides a link for you to go to their website and "confirm your details" - but the website is a fake, and if you do enter your details they will be used to steal all your money. Note that a legitimate email from your bank should be addressed to you personally rather than "Dear customer" etc, and will never ask you to enter your PIN.

Pixel

(PICture ELement) All computer screen or printed images are made up of pixels, small square dots - the smaller the pixels, the higher the image quality.

Plug'n'play

(Plug and Play) A system where Windows automatically detects any new hardware that is plugged into the PC and adjusts to it without human intervention.

Podcast

An audio file that can be downloaded to a portable audio player or computer, usually speech.

Port

A socket on the back (usually) of a computer which allows you to plug in extra hardware such as a printer or modem.

Processor

The nerve centre of the computer : everything flows through it. Also called the CPU. The best known is Intel's Pentium series. The most important single specification on any PC is the speed of its processor, usually measured in megahertz (MHz), or latterly gigahertz (GHz).

Proxy server

A computer used to store copies of popular webpages at an ISP and provide them on request, to save having to fetch them from the website again.

Quad-core

PC processors which have four complete processors on the same chip, allowing computers to handle multiple tasks faster. See also dual-core.

RAM

(Random Access Memory; pr. "ram") The computer's main memory, which it uses to hold whatever you are currently working on. The contents of RAM are lost when the computer is switched off. Adding more RAM is often the most cost-effective upgrade for an ageing computer.

Reboot

Restart the computer, either by shutting it down properly and restarting it (a soft reboot), or just switching it off and on again (a hard reboot - should only be used as a last resort).

Registry

A file on Windows PCs which contains all the settings for the PC and its software. Can be edited by the user, but this should only be done as absolutely a last resort, as it is possible to trash the operating system if you don't know what you are doing.

ROM

(Read Only Memory; pr. "rom") Memory whose contents are preset and cannot (usually) be changed by the user. See also CD-ROM.

Router

A device used to connect networks together, for example so that several PCs can share one internet connection. A relative of the hub, but more powerful.

Safe Mode

A cut-down version of Windows which you can launch instead of the full version for troubleshooting purposes.

SATA

(Serial Advanced Technology Attachment) A high speed standard for connecting hard disks to your computer, replacing EIDE on most new computers.

Scanner

A device which makes high-resolution copies of printed images and text to use on a computer.

Server

A computer at the centre of most networks which provides files and other services to other computers. Also known as a file server.

Shortcut

In Windows (from 95 on), a type of icon which lets you launch a program quickly, without having to search for it. Often placed on the Windows desktop for convenience. Usually has a small arrow in the bottom lefthand corner, to show it is a shortcut rather than the program itself.

Smartphone

A computer in a cellphone. As well as a phone, typically it will include both stills and movie cameras, music player, enough computing power to run sophisticated programs such as office sofware and games, satellite navigation, and gigabytes of storage. The most famous is Apple's iPhone, but all the major manufacturers make them and they are where the IT industry is mostly focussed at the moment. Some think that they will completely replace most personal computers.

Soundcard

Originally an expansion card to enable the PC to make sounds more sophisticated than a simple "beep!". Now usually built into the motherboard.

Spam

Unsolicited bulk advertising, usually via email. Originally a name for mass postings to Usenet newsgroups advertising products or services, regardless of their relevance to the newsgroup. (The name comes from a famous Monty Python sketch in which every conversation is interrupted every few seconds by people shouting "spam spam spam" at the top of their voices). Sending spam is illegal in most jurisdictions. A spam filter is a program designed to automatically remove spam from your email before you see it.

Spyware

Programs, typically installed by stealth, which record what you do on your PC and send reports to criminals, allowing them to steal your bank details, passwords and so on. See also Malware.

Standalone

A computer not connected to any kind of network.

Storage

The generic term for any method of storing information which is not lost when the computer is switched off; the most common types are hard disks, CDs, and DVDs.

Stream, streaming

Video or audio that plays while still downloading, rather than you having to wait till the download has finished.

System Tray

An area on the righthand end of the Windows Taskbar which displays icons representing TSRs presently running, usually at least a loudspeaker which represents the volume control for the soundcard, and a clock. Programs in the Sytem Tray are often but not always launched from the StartUp folder.

Tablet

A portable computer which consists only of a screen, usually with no keyboard. It is controlled using a touchscreen. The most popular is Apple's iPad, but all the major manufacturers are producing them.

Taskbar

In Windows, a bar across the bottom of the screen (usually - you can move it to the top or side if you want to) which contains the Start Button, the System Tray, and icons which represent all the applications currently running. You can switch between applications by calling up the taskbar and clicking on the relevant icon. The taskbar can be set to remain visible all the time (the default), or only to appear when you press the Windows key.

Thumb drive

A computer storage device about the size of a man's thumb, often carried on a keyring, which plugs into a PC USB port and is seen by the PC as an extra drive - a very convenient way to carry large amounts of data around.

Toolbar

An extra set of controls that can be added to many programs or the operating system, to provide extra functionality not present in the standard version. A toolbar often comes free with downloaded software and is intended to tie you to one company's products, especially internet search.

Torrent

A method of making data available for download over the internet, where the recipient of data is expected to make the data available to others for download from their PC, rather than all users downloading from a central server. Typically much of the data is bootleg software, audio and video. Because the data is distributed from multiple computers all over the place rather than a central point, it is difficult to police.

Trojan

A program similar to a virus which is disguised as something harmless like a game, but when launched actually sabotages the computer on which it is running.

URL

(Universal Resource Locator) An address used to locate something on the internet, most often a web page. All web addresses are URLs.

USB

(Universal Serial Bus) A standard type of connection port, used to attach extra devices such as a scanner to a computer. Standard on new PCs from around 1998. USB 2.0 and 3.0 are faster versions of the same thing. Many PCs now use USB to connect the mouse and keyboard.

VGA

(Video Graphics Array) An early colour graphics standard for PCs, now used as a sort of lowest common denominator which all monitors and graphics cards understand.

Virus

A program that has been deliberately created to cause computer problems, usually minor ones as a prank, but occasionally very nasty ones indeed, such as erasing your entire hard disk. Viruses were originally designed to attach themselves to programs on a disk, and then "hide" in the computer's memory once the host program is executed, and "infect" every disk they come across. Some types of virus (such as the famous "I love you") propagate by email, disguised as an attachment, which is why you should never open an attachment you are unsure of.

VOIP

(Voice Over Internet Protocol) A system for making cheap phonecalls over the internet instead of via the telephone system.

Wallpaper

A picture or motif on your Windows desktop. To change the Windows wallpaper right-click anywhere on the desktop, select Properties from the pop-up menu, choose the Desktop tab and select a new entry from the list under Background. To add pictures of your own to the list, save them as .bmp(bitmap) files and put them in your Windows folder.

WAN

(Wide Area Network) A sort of group of networks, or more properly LANs, connected together.

Webcam

(WEB CAMera) a kind of cheap TV camera which you can use for videoconferencing over the internet, or just showing off. They are very popular for making video calls over the internet.

Webmail

Email controlled from a website such as Hotmail or Yahoo instead of with a dedicated mail program like Outlook Express or Eudora. Many ISPs allow you to access your email both with a mail program and via the Web, so that you can access your email while traveling.

Webmaster

The person prinicipally responsible for maintaining a website.

Wi-Fi, WiFi

(WIreless FIdelity) A method of connecting computers to a network without cables, using small radio transmitter/receivers built in to most portable devices and broadband modems. Many hotels and other public locations now offer free WiFi if you have a suitable device, such as a laptop, tablet or smartphone.

Windows

A family of operating systems from the Microsoft Corporation, standard on most PCs. Windows 95, 98 and ME (Millenium Edition) were three generations of the early version intended mainly for home use; Windows NT and 2000, developed and released in parallel with the 9x family, were intended more for use in office and network environments. Both lines were replaced by Windows XP, which was first released in 2001, extensively upgraded since, and still popular today. XP was replaced first by Vista, released in 2007 to a lukewarm reception, then by Windows 7, released in 2009 and essentially Vista with the bugs taken out, which was much better received. The latest version is Windows 8, released in 2012, which has a new interface aimed mainly at touchscreens, as Microsoft try to move in to the fast-growing tablet and smartphone markets. However, it makes little sense on a desktop or laptop, Microsoft's biggest existing markets, and they fired the chief designer two weeks after it was released. Another version will no doubt be along shortly.

Wireless network

A computer network which uses radio transmitters (usually) to move information between computers without the need for physical cables. See Wi-Fi.

Wizard

A Windows feature which presents a user with simple menus or options for what would otherwise be a complex task, and carries them out automatically. Almost all Windows programs are installed via Wizards, and they are also widely used inside Windows programs.

Worm

A malicious program introduced into computers by stealth, similar to a virus.

Zip

A popular standard for file compression developed by the PKWare corporation. Files thus compressed usually have the extension .zip. See Winzip.