Can’t tell your hardware from your software? This plain English computer glossary introduces all the terms you need to get started with computers and the Internet.


access To gain entry to or connect to.

Access (Capital “A”). Microsoft’s database management program, available as a standalone product or as a component in some editions of Microsoft Office.

adware Advertising software that often accompanies freeware or shareware downloads. Adware displays advertisements while you use the accompanying program. It may also track your software usage or your surfing habits in order to target ads designed specifically to appeal to you.

Ajax Asynchronous JavaScript and XML. Ajax is a collection of existing technologies working synergistically. The ‘asynchronous’ part indicates that actions can occur independently of one another. For example, at the same time you are typing in a form the server can be feeding your browser additional information. JavaScript is a web coding language. XML (eXtensible Markup Language) is a data language used for exchanging information between the web page and the server. Ajax is really a misnomer, because the JavaScript element also includes dynamic HTML and CSS, while the XML function can be handled just as readily by server-side scripting languages like PHP or ASP.

API Application Programming Interface. A library of routines which gives third-party developers access to proprietary code, without letting them have direct contact with the code. For example, a company such as Amazon makes its API available to developers to help them create applications that access Amazon catalogs, products and services without exposing Amazon’s own code. The API provides ‘hooks’ or ‘calls’ into the code, which activate a particular function or return specific data (such as a book’s cover image, price, ISBN and so on).

alphanumeric Consisting of letters, numbers and special characters such as punctuation marks or spaces.

application A computer program designed to do a particular task or range of tasks. A word processor, a spreadsheet, a graphics program, a browser are all examples of applications. Applications software is sometimes contrasted with “utility software”, the latter being programs which make your operating system easier to use. The terms “applications”, “programs” and “software” are also sometimes used interchangeably.

Atom See RSS.


backdoor A hidden method of gaining access to a computer system. Backdoors, also known as trapdoors, are often inserted in programs by the programmer to help with debugging and access during development. When such a backdoor remains within a program, it can be used to breach system security.

back up To create a copy of files on a system. You should back up your data files regularly so you have spare copies if the originals are accidentally deleted or damaged.

backup A duplicate copy of a file.

back slash The \ character. On most computer keyboards the back slash key is located near the top-right corner of the main section of the keyboard, although this is not always the case. The back slash character is frequently used when describing the location of a file, as in:

C:\My Documents\Correspondence

Some computing old-timers use the terms slosh and slash for the forward slash (/) and the back slash (\) respectively. The slosh is used in web addresses.

bandwidth A measure of the amount of data able to travel through a particular connection. A high-bandwidth connection moves large amounts of data in a small time. Broadband Internet connections have high bandwidth. You will also hear the term used in reference to how much data a program may require. For example, online video streaming is a high-bandwidth application; that is, it requires high-speed transmission of large amounts of data.

BIOS Basic input/output system, pronounced buy-oss. Software built into your computer that controls basic communications, screen, keyboard and other functions. When your computer first starts up, it loads the BIOS before loading the operating system.

bit Binary digit. The smallest piece of information that can be stored by a computer. A bit can have a value of 0 or 1. There are 8 bits in a byte.

BitTorrent A peer-to-peer file distribution system, specifically designed for sharing large data files, such as video, over the Internet.

blog Short for web log. A blog is an online journal, displayed on a web page. It can be a personal diary, a commentary, a way to broadcast knowledge or information.

boot To start up a computer.

bps Bits per second, the standard measure of data transmission speeds.

broadband A fast communications technology capable of handling large quantities of data at high speeds. Most modern Internet connections use some form of broadband technology, such as fiber optic cable or DSL phone lines.

browser See web browser.

bug An error in a computer program or a flaw in computer hardware.

bus A set of wires used to transfer data between the main components on a computer’s motherboard.

byte A measurement of information stored on a computer. One byte can contain a single character – a letter, number, punctuation mark or other symbol. A byte is made up of a series of 8 bits.


cable modem A modem which operates over cable lines, providing high transmission rates.

CD-R Compact Disc Recordable. A drive that can create and read CD-ROMs and audio CDs. Also refers to the writeable compact disc media you place in a CD-R drive.

CD-ROM Compact Disc Read-Only Memory. A data version of the familiar audio CD. The ‘read-only’ indicates that while you can read information from CD-ROMs you cannot write information to them.

CD-RW Compact Disc Rewriteable. A type of CD that lets you write to it in multiple sessions (unlike a CD-R disc which can be written to only once).

central processing unit Also known as the CPU or microprocessor. The ‘brains’ of your computer. The CPU handles all the central logic and operations for your computer, assisted by other computer chips.

chip Short for ‘microchip’. A small piece of silicon (or another semi-conducting material) which contains electronic components such as transistors and resistors organised into a circuit. Your computer contains many chips, including the central processing unit, memory chips, and other support chips.

client A computer that accesses data or services from another computer, known as a server, over a network. Also, a piece of software that accesses the services of another piece of software (the server software) remotely. For example, an email client is a program you run on your computer to view email retrieved from a mail server.

clipboard A special temporary storage space in memory. Whenever you use the cut or copy commands in a program, the information is stored on the clipboard. It may be inserted into the current document using the paste command. The clipboard can contain only one item at a time, so each copy or cut command will replace the current contents of the clipboard.

configure To adjust a computer system’s or computer program’s settings so that it functions well.

cookie A small file placed on your hard disk by a website in order to identify you when you visit again.

CPU See central processing unit.

crash A serious computer problem that causes a program to halt or the whole computer to stop working.

cursor The small pointer that moves about the screen in a direct relationship to the movements of your mouse.

cyberspace The non-physical world created within computer systems. When you’re connected to the Internet, for example, you are ‘in cyberspace’.


data Any type of information. A letter you create with your word processor is data, as is a picture you draw using a graphics program. Data is stored on your computer in files.

default A standard or recommended setting which you may alter if you wish. For instance, the Windows Taskbar appears at the bottom of your screen by default; you can move it to another position by dragging-and-dropping it.

Desktop The full-screen display where all Windows activity takes place. Analogous to a real desktop.

device driver Also known simply as a ‘driver’. A piece of software which tells a piece of hardware how to work with the rest of a computer system. Your printer, for instance, requires a printer driver to make sure it works correctly.

device Any computer sub-system or peripheral, such as a printer, USB port or disk drive.

dial-up connection Internet service provided using a standard phone line and a modem. Dial-up connections are very slow and are not suitable for use with most modern websites.

dialog box, dialog An onscreen box which lets you adjust settings or provide information needed to run a program, or which is used to alert you to some event. Dialog boxes require some form of interaction between the user and the computer, hence the name.

directory See folder.

disable To prevent a feature or component from operating.

disc A storage medium using optical technology. The term includes CDs, DVDs and laser discs.

disk A computer storage medium (using non-optical technology).

diskette See floppy disk.

document Any self-contained piece of work created using a program. A letter you create with your word processor is a document; so, too, is a picture you create with a graphics editor or a webpage you design with a web page editor.

download To copy information from a remote computer to your computer. When you connect to the web, you’re constantly downloading web pages and files to your computer system.

DoS Denial of Service. An attack designed to bring a network to a standstill. A DoS attack floods the network with useless traffic.

drop-down menu Sub-menus which drop down from another menu. Also known as pop-up or cascading menus.

DSL Digital Subscriber Line. A communications technology that supports high-speed data connections.

DVD Digital Versatile Disc or Digital Video Disc. Like CDs, DVDs come in a variety of formats, including DVD-R, DVD+R, DVD-RW, DVD+RW and DVD-RAM. Each has its own advantages, although DVD-R and DVD-RW tend to be the most widely supported and compatible with a broad range of DVD drives in computers and DVD players in entertainment centers. Newer dual-layer DVDs hold around twice as much information as standard DVDs (up to 8.7 gigabytes), but require a drive with dual-layer capability to write them. DVDs created on dual-layer drives may be read on some, but not all, older DVD drives.


email Electronic mail. Messages exchanged between users on a network.

email address A unique name that identifies an email recipient. Email addresses take the form username@hostname. An example is, which is pronounced ‘johndoe at morgue dot com.’ Note that email addresses, unlike URLs (Internet addresses), are not case sensitive.

enable To allow a program feature or a computer device to function.

ergonomic Designed to enhance human comfort and performance.

execute To run a computer program.


Facebook A popular social networking site.

FAQ Frequently Asked Questions (pronounced fak). Documents that give the answers to commonly asked questions about a particular topic.

feed A document containing a summary of stories (essentially headlines) with links to longer items on the same topic. Blogs are common sources of feeds, and by using a feedreader to subscribe to a blog’s feed, you can quickly see a list of the latest entries in a blog and click a link to see the full entry.

feedreader A software application for reading and subscribing to feeds. There are dedicated feedreaders, such as FeedDemon, and also feedreading capabilities built into other programs, including browsers such as Internet Explorer 7, Opera and Firefox.

file A collection of related information stored on a computer. Each document you create is stored in a file with its own filename, so you (and the computer) can identify it. Programs, too, are stored in files.

file extension Each file on your computer has a filename which uniquely identifies it. In pre-Windows times, when people used DOS as their operating system (the acronym stands for Disk Operating System), filenames were limited to a name of up to eight characters followed by a full stop (that’s a period for my US readers) followed by an extension of up to three characters. If you ever see the term 8.3 filename this is what it refers to. The file extension usually indicates the type of file: DOC for documents, JPG for images in JPG format, XLS for Excel spreadsheets, and so on. Windows is much more liberal with filenames. It lets you use up to 215 characters, including spaces and most punctuation marks except the following:

/ \ : * ? ” < > |

firewall A security program that monitors ingoing and outgoing activity on your Internet connection and blocks suspicious or unauthorized access to your computer.

flame A vicious email message or newsgroup posting in which the author attacks another online participant.

floppy disk A small, removable storage medium. Floppies are so-called because inside the rigid protective case is a flexible, brown plastic disk on which data can be stored. To use a floppy, you insert it in a floppy disk drive. Although floppies are rarely used these days, having been replaced by higher capacity, more efficient storage media, some computers are still supplied with floppy disk drives to allow you to use old floppy discs.

folder A file container on a disk. Like a folder in a filing cabinet, you can store related files in the same folder to help organize your information.

FTP File Transfer Protocol. A commonly used method for transmitting files across the Internet. FTP is often used by website creators to copy content from their computer to the web server which hosts their site on the Internet.


G, GB See gigabyte.

geotagging Adding location information to digital photos, websites or other items. Geotagged photos, for example, may by overlaid on a map.

gigabyte A measurement of memory. One gigabyte (1GB or 1G) is equivalent to 2 to the 30th power (1,073,741,824) bytes or 1024 megabytes.

GUI Graphical User Interface, pronounced gooey. Windows is a GUI. That is, it is made up of graphical elements (windows, icons, menus). Contrast this with earlier operating systems such as DOS, which were purely textual with commands entered by typing.


hang See crash.

hard disk A device where you permanently store programs and data. Also called a hard drive, hard disk drive or HDD. Hard disks are usually installed inside the main computer housing. Almost all computers come with at least one internal hard drive. External hard disk drives that connect via a computer’s USB or FireWire ports are now commonly used for backup purposes and for storing large collections of audio and video files. These external drives can be stored in a safe location away from the computer to protect the data, or moved from computer to computer, making it easy to transfer very large files.

hardware The physical equipment that makes up a computer system. Hardware is essentially the parts of a computer you can touch – the monitor, keyboard, disk drives, and so on.

home page The main page of a website.

HTML Hypertext Markup Language, the authoring language used to create documents on the World Wide Web.

HTTP Hypertext Transfer Protocol. The set of rules governing the transmission of documents on the World Wide Web.

HTTPS Hypertext Transfer Protocol (Secure). A version of HTTP that provides encryption and authentication of sensitive documents. Sites that accept payment transactions, such as banks and PayPal, use HTTPS. You should not submit sensitive information including bank account numbers on sites that don’t use HTTPS. You can identify such sites by the https:// prefix in the address box of your web browser; most browsers also show a padlock icon in the status bar of sites using HTTPS.

hyperlink An element (piece of text, graphic image) in a document that links to another place in the same document or to an entirely different document. When you click a hyperlink, you jump to the link’s location. The World Wide Web is composed of documents which use hyperlinks for interconnection. Text-based hyperlinks are often displayed in a different colour or underlined, so they stand out from the rest of the document. Images may also have a hyperlink embedded within them, so when you click the image you jump to the embedded link’s location.


icon A small on-screen picture which represents something: a program, a folder, a data file, a command shortcut.

IMAP Internet Message Access Protocol. A newer alternative to POP, for retrieving email messages from a mail server.

input Information entered into a computer, or the act of entering such information. You can input information using input devices such as the keyboard, mouse or a scanner.

interface A term most often used to describe the ‘user interface’, which is the way a computer system or program is designed to work with its human operator.

Internet A global system of computer networks, allowing communication and information exchange. Although many people use the terms “Internet” and “web” interchangeable, they are not the same. The web is a system of sharing information on the Internet. Other services which use the Internet are email, newsgroups, instant messaging, and so on.

Internet address See URL.

Internet telephony See VoIP.

in the cloud Applications and data stored online. In the cloud model of computing, you use your computer or mobile device to tap into remote data stores and processing resources.

IP Internet Protocol. A set of rules determining the structure of packets of data passed around a network. IP includes rules for addressing those packets so they reach their intended destination. The Internet is built upon two main protocols: IP and TCP (Transmission Control Protocol), and is known as a TCP/IP network.

ISP Internet Service Provider. ISPs maintain a dedicated communication line to the Internet; users connect to the ISP via a modem, and the ISP then connects them to the Internet via a dedicated communications line.


JavaScript A scripting language for the web. Web authors use JavaScript to automate actions on their sites and perform sophisticated functions.

JPG or JPEG Pronounced jay-peg. A graphics file format which can compress graphics to a fraction of their size. JPG uses ‘lossy compression’, which means that the higher the degree of compression, the more detail is lost from the image. JPG images are frequently used on web pages because their small size reduces download time and, thus, the time it takes to load a web page that contains images. Images in JPG format have the file extension .jpg (or, occasionally, .jpeg).


K, KB See kilobyte.

Kbps Kilobits per second. A measure of data transfer speed. One kilobit is 1,000 bits. A 56Kbps modem (ideally) transfers information at 56,000 bits per second. If you divide the Kbps rate by 10, you’ll get the approximate number of characters transferred in one second.

key logger A program (or hardware device) designed to record everything you type on the keyboard.

kilobyte A measurement of memory. One kilobyte (1KB) holds 1024 bytes.


LAN Local Area Network. A group of computers connected together within a fairly small geographical space, usually within one building.

link Also known as a hyperlink. A dynamic reference to another document (or another part of the current document). Clicking a link will connect you to the destination document.

Linux An operating system which runs on a variety of computer hardware, including PCs. Linux has a very strong following due to its efficient design and because it’s offered free of charge under a system called open source. However, despite attempts to make a user friendly version of Linux, it is far more difficult to use than either Windows or Mac OS and is not suitable for beginners.

log off, log out See sign off.

log on See sign on.

logic bomb A piece of malicious code buried within another program, designed to go off when triggered by a particular event. Logic bombs are often laid by disgruntled, technically competent employees.


M, MB See megabyte.

Mac OS An operating system designed by Apple which is used on Macintosh computers.

macro virus A computer virus that exploits the macro coding language available in some applications, in particular Microsoft Word and Microsoft Excel. While most viruses are delivered as executable programs, macro viruses come stored within a document and activate when the document is opened.

mashup A web application which integrates data from multiple sources into a single tool.

Mbps Megabits per second – millions of bits per second. A measure of data transfer speed.

megabyte A measure of computer storage. One megabyte (1MB or 1M) is equivalent to 1,048,576 bytes. All information in your computer is measured in bytes, with one byte containing the equivalent of a single character, such as a letter of the alphabet, a number, a punctuation mark (including spaces) and so on. These days, hard disk sizes are usually measure in gigabytes—1,073,741,824 bytes.

megahertz A measure of frequency. Used to measure microprocessor speed.

memory Random Access Memory (RAM). Temporary storage area for programs and data while your computer is switched on. Anything stored in RAM is lost when the power is turned off. Don’t confuse memory with storage (such as hard drives), which is a permanent data store.

menu A list of options from which you can choose. You open a menu by clicking its title with the mouse; then you select an option by moving the mouse pointer to the desired option and then clicking.

MHz See megahertz.

microcomputer A computer built around a single microprocessor, such as a PC or a Mac. These days the definition is getting stretched as microcomputers are frequently built with two or more microprocessors working together.

microprocessor A silicon chip that contains a central processing unit. The term is often used interchangeably with the term central processing unit when talking about personal computers.

modem Modulator-demodulator. A device used to transmit digital data (from your computer) across phone lines or optic cable.

motherboard Sometimes called a main board. The main circuit board in a computer, holding the primary components such as the CPU and RAM.
mouse A pointing device which lets a user interact with a computer.

MP3 A compressed audio format that has gained huge popularity. Thousands of musical tracks are available in MP3 format on the web, and you can download these tracks using a browser or other software and listen to them on your computer or a portable MP3 player.

multimedia The use of sound, video and/or animation as well as static graphics and text.

multitasking A system which can perform more than one task at a time. Both Windows and Mac OS are multitasking operating systems.


nanosecond One billionth of a second.

netiquette Etiquette guidelines for behavior on the Internet, in particular with regard to posting messages to newsgroups and email.

network Two or more computers linked together.

newsgroup An online discussion group on a particular topic.

newsreader An application that lets you read and reply to messages posted on Internet newsgroups.


offline Disconnected from a computer communications system.

online Connected to a computer communications system.

open Also called run, load, start or execute. Opening an item (such as a program) activates it.

OS See operating system.

operating system A collection of programs which, together, manage all the basic functions of a computer. The operating system runs other programs (such as a word processor or graphics editor), manages the storage of your own documents, and coordinates the functions of the computer itself and all the devices connected to the computer. Windows Me, Mac OS and Linux are three examples of operating systems. A program written to work under one operating system will not work on another operating system (a different version must be written for each operating system – such as Microsoft Office for Windows and Office for the Mac.)

output Information processed by a computer program and displayed or stored on a device. Output may be printed, displayed on the screen, sent across a communications link, played through the speakers, and so on.


P2P See peer-to-peer.

packet switched network A network in which information is passed around in packets known as datagrams. The Internet is an example of such a network. When you send any form of data across the Internet – whether it is text, images, video clips, audio – the data is first chopped up into chunks. Each chunk of data not only contains part of the original data, but also a packet number indicating where it fits in the stream of data packets created from the original, plus the destination address. Your computer sends the packets to a nearby router; the router checks the address and passes each packet on to another router, and so on until the packet reaches the appropriate address. Packets are routed along the least congested paths, so not all packets will follow the same route to their destination. Once all the packets arrive at the destination, they are reassembled, using the packet numbers, into a complete whole once more.

parallel port See port.

patch A software Band-Aid. Code applied to existing code to fix or circumvent a problem in the underlying software.

PC Personal computer. Usually used to refer to any computer that runs the Windows operating system as opposed to a “Mac”, which is a computer designed by Apple and running the Macintosh operating system.

PDF Portable Document Format, also known as an Acrobat file. A file format, developed by Adobe, which lets people create documents that look the same viewed on any computer system or when printed by any printer. The PDF format also lets the document author lock the document to prevent changes by others, and thus protect the integrity of a document. To create a PDF document, you need to buy Adobe Acrobat (or a compatible program); however, anyone may view a PDF document using the free Adobe Reader, available from

peer-to-peer Also known as P2P. A network of computers in which information is transmitted directly between computers in the network, rather than using centralized servers to store and supply information. Peer-to-peer networks are often adhoc in nature, with computers joining and leaving the network at will. Peer-to-peer networks are used for applications such as file sharing and for Internet telephony. Because such systems avoid the use of centralized servers and computers join and leave the network on the fly, they are hard to control, one reason why P2P networks are frequently used for sharing pirated software, music and video.

Pentium A family of microprocessors from Intel.

peripheral Hardware component that you add to the central system unit of a computer, such as a monitor, printer, mouse, scanner or digital camera.

pirated software An illegal copy of copyrighted software.

phishing A scam designed to glean important information from the victims by sending them email that appears to come from a legitimate source. The email usually contains a link to a fraudulent website (known as a ‘spoofed’ site), where victims are fooled into entering passwords, account numbers and other sensitive information.

platform The hardware or software on which software applications are run. The iPhone, Intel-based PCs and the Kindle ebook reader are all examples of hardware platforms; Windows, Mac OS X and Linux are all examples of software (operating system) platforms.

Plug and Play The ability to configure a new device automatically. Also known as PnP.

podcast An audio or video file published over the Internet using RSS or Atom syndication. Users may subscribe to a podcast and receive new episodes automatically via software known as a podcast receiver or podcatcher.

POP Post Office Protocol. A set of rules for retrieving email from a mail server.

port A conduit for transferring information between a computer and an external device, such as a modem, mouse, joystick, digital camera or printer. Parallel ports (used by printers and scanners) transfer bits of information simultaneously in groups. Serial ports (used by modems and joysticks) transfer information one bit at a time. Both these types of ports are being replaced by speedy and flexible USB ports.

post To place a message on a newsgroup or BBS.

processor See microprocessor.

protocol A set of rules for passing data from one device to another. Protocols determine

such things as the type of error checking and compression used and establish methods for the receiving device to acknowledge it has received a packet of data, and for the sending device to indicate when it has finished sending data.

PSTN Public Switched Telephone Network (sometimes called POTS: Plain Old Telephone System). In contrast to the Internet, which is a packet switched network, the PSTN is a circuit-switched network. In a circuit-switching network, when you want to transmit information between two points, you establish a connection between those points and maintain that two-way connection for the duration of the call. So, when you pick up the phone, you first listen for a dial tone indicating a connection to your local telephone company, you dial the number, your call is passed through the local switch and possibly through a number of intervening switches to its destination where the phone rings, the person you called answers, and a circuit is created, remaining open until one of you hangs up.

public-domain software Any program that is not copyrighted, and is thus available for free use by anyone. (Note that ‘freeware’ is copyrighted software that is free.)


RAM Random Access Memory. The fast internal memory used by the computer to store information and instructions while the computer is operating. Anything stored in RAM is lost when the power is switched off.

resolution The clarity of the image on the screen. Screen resolution is often measured in pixels (picture elements), with common resolutions being 800×600 and 1024×768.

ROM Read-Only Memory. Internal memory which contains permanent instructions.

RSS Really Simple Syndication. RSS is a way for one site to allow publication of some of its content on other sites—very much in the way some newspaper columnists have their articles syndicated across national or international publications. The RSS content, known as a feed, can also be downloaded directly by anyone who has a program called an RSS reader or a feed reader. Using RSS is like having headlines from multiple news sources delivered to your desktop; a click on any headline delivers the entire article. Atom is an alternative syndication format to RSS.


scroll To move a document in a window so you can see any portion of it. You can scroll up and down or side to side using scrollbars to the right and bottom of the window.

SCSI Small Computer System Interface (pronounced skuzzy). A high performance design for connecting disk drives, scanners and other devices to a computer.

search engine A service which searches pages on the Internet for specified keywords and returns a list of the pages containing the keywords. Examples include Google and Bing.

serial port See port.

server A computer that provides a service to other computers via a network. Servers are often dedicated to a specific type of service. A file server, for example, is used as a central file store for a group of computers; a web server stores web pages and delivers them to web clients (known as browsers) on request.

setup, set up To install and configure computer hardware or software. Most computer applications come with a setup program which steps you through this process.

shareware Software which you can try out without payment. If you continue to use the software, you are honor-bound to pay the author the requested fee.

shortcut A pointer to a file. Creating a shortcut allows you to quickly access a program or document no matter where it’s actually stored. The Mac equivalent is called an alias.

sign off, sign out To finish a session on a computer system or network.

sign on To start a session on a computer session or network. By signing on, usually by entering a username and a password, you let the system know you are connected.

SMTP Simple Mail Transfer Protocol. A set of rules for sending messages between mail servers, and for sending messages from email clients to mail servers.

social networking Sites and technologies that encourage the creation of personal networks as a way of community building. Members of social networks may share interests, activities, news and online resources. Facebook and MySpace are two popular social networking sites. Virtual worlds, such as Second Life, also serve as social networking services.

software A generic term for computer programs. A program is a series of instructions used to manipulate data or to control the workings of a computer system. Programs used to manipulate data are often called applications software, while programs used to control the workings of a computer system are known as operating systems software. A word processor is an example of applications software; Windows 7 and Mac OSX are examples of operating systems.
spam Electronic junk mail.

spoof To fool by masquerading as something else. Email spoofing involves forging the header so the From: address makes the message appear as if it came from someone else. Website spoofing fakes the address shown in the address bar. Spoofers also mock up the content of the message or site so it matches a legitimate service.

spyware Software installed without your knowledge or full, informed consent, which tracks your computer usage and/or online activities. Usually used to target advertising in some freeware or shareware programs, but also used entirely illicitly to spy discover crucial personal information.

status bar A section of an application window in which summary information is displayed. The status bar is usually located at the very bottom of the window. By looking at the status bar in your browser, for example, you can gain useful information about the site you’re viewing and the progress of your connection.

storage Any medium or device (such as a hard disk) used to store data for an extended period.

surf To move from place to place on the Internet, usually using a web browser.


Taskbar The long horizontal bar at the bottom of the Windows desktop. You use the taskbar to access programs and manage your desktop.

TCP Transmission Control Protocol. A set of rules for establishing a connection between computer hosts. Together with the Internet Protocol, TCP is one of the two set of rules used to determine how data is transmitted on the Internet. When data is sent across the Internet, it is first broken into small equal-sized packets, with each packet being given the same address. The separate packets may follow different routes to the destination, where they are reassembled. IP governs the format of the data and its addressing; TCP establishes the connection between the sending and receiving computers and also ensures that the data packets are delivered in the same order as they were sent, so they can be reassembled correctly.

terabyte A unit of measurement. One terabyte is equivalent to 1000 gigabytes. In 2007, the first terabyte-capacity hard disk drives were released.

title bar The top-most portion on an application window. The title bar contains the name of the currently open document, the name of the application in which the document is opened (such as Microsoft Word or Internet Explorer) and, in the right-hand corner, buttons for minimizing, restoring and closing the window. Double-clicking the title bar alternately maximizes and restores the window.

toolbar Icons grouped together within a program, usually in a strip across the top of the window. Each toolbar icon or ‘button’ provides a shortcut to one of the program’s commands or features.

tooltip A short, informative message which pops up when you let the mouse pointer linger on an icon, menu option or other part of the user interface.

traffic The amount of information being handled by a communications system. During times of heavy traffic on the Internet, you may notice your connections slow.

Trojan Short for Trojan Horse. Malicious code disguised as a benign program. When you run the program, its payload is launched. Trojans can also be embedded in documents, and when the document is opened, the Trojan runs as a macro virus. Trojans are now being used to deliver key-logging spyware which, when activated, starts tracking every key you press on your computer.

tweet A message sent using the micro-blogging service Twitter.

Twitter A micro-blogging and social networking service that poses the question “What are you doing now?”, with replies limited to 140 characters.


undo To reverse your last action in a computer program. Many programs allow multiple ‘undos’ so you can reverse a whole series of actions.

unzip To decompress a file that has been compressed using a program such as WinZip.

upload To send information from your computer to a remote computer.

URL Uniform Resource Locator, the address used to identify documents and other resources on the Internet.

USB Universal Serial Bus. A high-speed connector that lets you connect up to 127 different devices to your computer. USB 2.0 is the most recent standard, and it’s much faster than the original USB 1 and 1.1. USB 2.0 provides backwards compatibility, so you can attach older USB 1 devices to a USB 2.0 port and they will still work; however, you’ll need to use USB 2.0 devices connected to a USB 2.0 port to get the high speed advantage of the newer technology.


videoblog Also known as a vblog. A videoed blog.

virtual Not real. Something which is virtual has no physical basis itself but mimics a physical object in conceptual terms. For instance, on the web you’ll find graphical representations of buildings which you can ‘walk through’ using your mouse. Such a building is a virtual building and it may be part of a larger virtual world.

virtual world A simulated environment in which participants create online identities, known as avatars, to interact within the environment. The best known virtual world is Second Life, where people can create personas, interact with other personas, explore, build, learn and transact business.

virus A computer program designed to replicate itself. Many computer viruses are innocuous, some are harmful and can either damage information and programs on your computer or cause your computer to malfunction.

vodcast Also known as vcast. A video version of a podcast.

VoIP Voice over Internet Protocol, also known as Internet telephony. A phone system that runs on the Internet instead of the traditional public switched telephone network (PSTN). One of the best-known VoIP software applications is Skype (, a program that lets you make “phone calls” from your PC to another PC running Skype or to any standard or cellular phone.


web Short for World Wide Web. A collection of online documents (“pages”) stored on interlinked computers, called web servers, around the globe. Web pages are created using a number of languages, the most common being HTML (Hypertext Markup Language), a language that supports linking from one document to another. Web pages may include text, images, video, sound and even programs designed to run online. Users can view the pages using a web browser, and can jump from document to document by clicking on the links contained in the documents. The web is only a part of the Internet – some Internet servers perform functions other than being web servers. For example, mail servers store and handle email; news servers store and handle newsgroups.

web browser A software application used to locate and display web pages.

web server A computer on the Internet that stores web pages and delivers them to web browsers on request.

website A location on the World Wide Web, consisting of at least one page (the home page) and possibly many pages.

WEP Wireless Equivalency Protocol. A security standard for wireless networks, commonly available but not as secure as the WPA standard.

wiki From the Hawaiian wiki wiki, meaning ‘quick’. A wiki is a communal blog or website. It can be edited on the fly by a restricted group of people; by any member of the site; or, sometimes, by anyone who visits the site. The most famous wiki is Wikipedia (, a communal online encyclopedia.

window A portion of the screen used to display a program, document or data.

Windows An operating system designed by Microsoft. Most home users use Windows XP, Windows Vista or the more recent Windows 7.

Wintel A computer that contains an Intel (or compatible) microprocessor and which runs Microsoft Windows. That’s almost 90 percent of the personal computers in the world.

WLAN Wireless local area network. A network that uses wireless technology to share information.

worm Code that replicates itself and sometimes causes damage to the computers it infects. A mass-mailing worm uses email to replicate itself. Mass mailing worms, when activated, often scan an entire computer system for email addresses (not just in contact lists but also within documents), and then email themselves to those addresses. The worm either uses the email address of the infected machine in the From: field of the infected messages it sends; or it may use one of the addresses it has discovered on the infected machine in the From: field. This is why, even though your PC may be completely free of infection, people will email you saying “Why did you send me an infected message?” In these cases, your address has been scooped up from someone else’s PC.

WPA Wi-Fi Protected Access. A security standard for wireless networks, that provides better security than the older WEP. An even stronger version, WPA2, is also available.


zip To compress a file using a program such as WinZip. You zip files to package numerous related files together and to make them smaller, so they are easier to store on disk or to send to another user via the Internet. Windows XP comes with a built-in zip compressor.

zombie An unsecured computer which has come under the control of a hacker. The hacker uses a piece of code called an agent or daemon to control the zombie without its user’s knowledge. Zombies are frequently used as launching pads for other attacks, in particular Denial of Service(DoS) attacks.