Glossary of Computer and Internet words
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To find out how to use the internet, please read the rest of this guide. This glossary gives the meanings of words that you may find on the internet. To look up a word just click on its first letter in the alphabet below, or just scroll down. Terms can have several forms (with/without spaces or hyphens). If you can't find something, try using just one of its words or running its words together.


An address on the internet can be either an email address, or a web address.

Adobe Acrobat is the software that reads a type of file called 'pdf', which always looks the same (webpages appearance may vary). If a webpage offers 'pdf' files, it may let you download Adobe Acrobat. Without it, you won't be able to look at any 'pdf' file.

The address box is the white rectangle near the top of the
browser screen, where you type in a web address.

ADSL is a method of accessing the internet through ordinary phone lines which is quicker than usual. It needs a special modem and it also needs to be supported by your ISP.

An application is a computer program.

An attachment is something attached to an email, such as a picture. Some attachments can carry viruses.

The Back button takes you back to the previous webpage. Click here for more on Back.

Bandwidth describes how quickly data flows down a telephone line or through a modem.

baud means the same as bps.

Bookmark is the Mozilla term for Favorite (used by Internet Explorer).

bps measures the speed of a modem. It means 'bits per second'.There are 8 bits to a byte.

Broadband is a high bandwidth connection to the internet which is always on and available for a flat rate.

The browser is the computer program which allows you to use the world wide web. The top few lines of this screen are the browser. It has different functions like Back, Forward, Home, Print, Favorite (or Bookmark) and History. It also has the Address box. The two main browsers are Internet Explorer and Mozilla.

A bulletin board is a web-based way to post messages so they can be read by other people.

A button on a computer screen is a small coloured box which is a link. A mouse button is something on the mouse that you click.

A byte of data is a very small amount of information, just one letter or one digit of a number. So we usually talk about thousands of bytes (kilobytes, KB), millions (megabytes, MB), or even billions (gigabytes, GB). A 1KB file is small. Hard disks have gigabytes of data.

The cache is where a computer stores data (such as webpages) that may be needed again. Loading a webpage from the internet for the first time is slower than going back to it (when the computer uses its cache). Use the Refresh button to get the up-to-date version of a webpage, rather than the cached version, .

A CD is a compact disc. It can have music on. It can also store data or software. Unlike a hard disk, it can be moved between computers. Ordinary CDs can only be read, not written to.

A CD-RW is a type of CD which can be written to as well as read from. You can write to it more than once. You need the right sort of disk drive to handle CD-RWs.

A CD-R is a type of CD which can be written to as well as read from. However, you can only write to it once. You need the right sort of disk drive to handle CD-Rs.

A chatroom is where people 'talk' to each other using the internet. Some chatrooms are web-based, while some use special software, which has to be downloaded.

Click means pressing the left-hand (or only) mouse button once. 'Double-click' means pressing it twice in quick succession. If you don't know whether to click or double-click, try clicking, and if nothing happens, then double-click. If nothing still happens, then press the Enter key on the keyboard. The internet only requires single clicking.

Close means finishing a program or a window. Click here to see how to close a window.

Compress means to reduce the amount of space some data takes up, so it is quicker to load or download.

To connect to the internet is to start the telephone call which connects your computer with all the other computers in the internet. The telephone call continues until you disconnect. Broadband connects to the internet automatically when the computer is switched on.

A contact form on a webpage allows you to communicate with its webmaster.

A cookie is some data that a webpage stores on your computer when you visit that webpage. Cookies cannot contain viruses. They enable the webpage to remember what you did last time, how often you've visited the webpage, and so on.

Crash means 'Help! This computer has stopped working!'. Switching it off, and on again may be all it needs to fix it.

Cyberspace means the same as the internet.

Data is anything that can be handled by a computer. It is often called 'information', but can be text, sound, pictures, programs or games. A collection of data is called a file. Data is measured in bytes.

Debug means take the errors out of a computer program. Unfortunately some webpages still contain errors (bugs). Sometimes you get an error window asking you if you want to debug the webpage. Click on No.

A desktop computer is a personal computer, which is too big to be portable. It contains the disk drives, modem, hard drive and processor. It has a separate keyboard, and a screen like a television. It usually has a mouse and a printer. It may have a scanner, speakers and perhaps other hardware as well. It may need its own desk!

To dialup means the same as connecting to the internet.

A digital camera works like a normal camera, but stores the photographs on little cards (like disks) instead of on film. You can then put the photographs straight into your computer to look at them, print them out or put them on the internet, rather than having to wait until they've been developed.

To disconnect from the internet means to stop the telephone call which connects you to the internet. .

A discussion forum allows people to exchange views (generally on common interests) via the world wide web. Their comments are organised into topics called threads. You can comment on previous comments, or start a new thread.

Disks store data. There are floppy disks, hard disks, CDs, CD-RWs and CD-Rs although floppy disks are becoming old-fashioned. USB sticks are replacing them.

The domain name is the key part of an internet address. A web address starts with the domain name which ends with the first /. The domain name of this website is, and all its webpages have web addresses beginning with that. You can tell something about a website from its domain name. If it ends .uk, then it is British. A means a British company, is a UK government site and so on. An email address has its domain name after the @. Email addresses do not contain www.

dot com or (.com) is the ending for the domain name of the website of an American company (or a company that wants to look American). It is used to refer to new companies trying to make money from the internet, but is also used by long-established companies.

Download means copy something from the internet to your own computer. Click here to find out more about downloading.

Disk drives are where you insert disks in a computer.

A drop-down menu is a common way to select from a range of choices on a webpage. Click here to find out more about drop-down menus.

DVDs are a type of CD-ROM that can contain enough data to hold an entire film. You need a DVD drive to play a DVD.

E-commerce means 'doing business' on the internet, such as shopping.

Email (or e-mail) is electronic mail. Click here for our guide to email, or here to set up your own email account.

An email group communicates through emails sent to the whole group.

An email address contains @. To send someone an email, you need their email address. Don't confuse this with a web address.

The Enter key on the keyboard is the big key, a few keys to the right of the letters P and L. If something should be happening, but isn't, try pressing the Enter key.

FAQ stands for Frequently Asked Questions. Many websites offer FAQs (with answers).

The Favorites button lists links to your favourite webpages. Click here for more on Favorites.

A file is a collection of data. You need the correct program to use a particular file type. You can open a file (so you can look at it), close it (when you've finished with it), save it (if you have changed the data), execute or run it (if it's a program), play it (if it's music) and print it (if it's writing or pictures). A webpage is a file, and so is each picture on a webpage. Every file has a name. Files are kept in folders.

To flame someone is to communicate in a hostile way via the interactive internet.

Flash is software used on webpages. Simple webpages are written in HTML. Flash webpages have special effects, but they take longer to load and you may need to download the Flash software to see them.

A floppy disk stores about 1 million bytes of data. You can save data from one computer onto a floppy disk, and then take the floppy disk to another computer to use the data. However modern computers may not have a floppy disk drive. They use USB sticks instead.

A folder is a place for storing files. There are so many files in a computer that they have to be organised so you can find them, so you group them in folders.

A forum is short for a discussion forum.

The Forward button reverses the Back button. Click here for more on Forward.

Frames on some webpages divide the webpage into different parts. When you click on a link or scroll up or down, only part of the webpage changes. The web address doesn't change when you move between webpages.

A gamepad is used to play computer games.

GB or gigabyte is a billion (1,000,000,000) bytes.

A gif is one type of compressed picture.

A hard disk stores data permanently in your computer. You will probably never see it. It stores your operating system. The reason that it takes so long to switch on a computer is that lots of programs have to be copied from the hard disk to the computer's memory. These programs can't stay in memory all the time, because it's too small. Everything in memory disappears when you switch the computer off, or it crashes. When you save a file, you usually save it to the hard disk (although you can save it to a floppy disk).

Hardware is the bits of a computer that you can touch, made of metal, plastic, wires etc. It includes the screen, keyboard, mouse and printer, as well as the actual computer. See software.

A hit is one visit to a webpage. Some webpages count how many people have visited them, and proudly display the number. Alternatively, a hit is a link found by a search engine.

The Home button goes to the computer's homepage (not the website's homepage). Click here for more about homepages.

The homepage of a website is its first webpage. A computer's homepage is the first webpage that you see when you connect onto the internet. Click here for more about homepages.

HTML is how webpages are written. It includes the text, pictures, links, and instructions for formatting the webpage. To see some HTML, click on 'View' on the top of the screen, then 'Source'. To write webpages without learning HTML, use a program that lets you design the webpage easily and then turns this into HTML. You will also need webspace on your server and some software to transfer your webpage onto the internet.

http:// stands for 'hyper-text transfer protocol'. This begins nearly every web address (look in the address box at the top of this screen). However, when you type a web address, you start with the www. The computer will put http:// back in for you.

A hyperlink is another word for link.

An icon is a small picture on a computer screen. You click or double click on it to make something happen (like starting a program).

The information super highway is a pompous term for the internet.

An insertion is another word for an attachment.

The interactive internet allows you to communicate with groups of like-minded people. It may be a bulletin board, discussion forum, newsgroup or email group.

The internet is a network of millions of computers, connected by telephone lines. It contains both the world wide web and email.

An internet cafe is offers the use of computers connected to the internet for a charge. You will be able to use the world wide web, and web-based emails. You may also be able to buy coffee!

Internet Explorer is a browser. If you have a PC, look at the top left or top right of this screen, where you might see the symbols for Internet Explorer (Windows Explorer symbol, Windows Explorer symbol, Windows Explorer symbol or Windows Explorer symbol). All Microsoft Windows operating systems use a version of Internet Explorer.

ISDNs are fast phone lines mostly for business internet use.

An ISP, or Internet Service Provider, is a company that can connect you to the internet. It has a computer called the server. Click here to find out more about ISPs.

Java is a computer langauge. Simple webpages are written in HTML and don't do much except let you read them. However, some webpages do clever things, carried out by Java programs called applets. These can take a little time to start.

A joystick fufils the same purpose as a mouse in a different way. It is used on laptops and for computer games.

A jpeg or jpg is one type of compressed picture.

KB or kilobyte is a thousand bytes.

A search key is one or more words that you type into a search engine, so it can find webpages containing those words.

A computer language is used for writing computer programs. Luckily you can use a computer without knowing anything about computer programming langauges.

A laptop computer is a personal computer, which is portable (just). It combines a keyboard, a flat screen, disk drives, modem, hard drive and processor in one brief-case shaped unit. This unit also contains a roller-ball, a joystick or a touchpad instead of a mouse.

A link is the part of a webpage that you click on to go to another webpage. Click here for more on links.

The loading of a webpage starts when you click on a link or enter a web address. It finishes when the finished webapge appears on your screen. This can take a few seconds, or, in extreme cases, several minutes. Webpages can be slow to load because another computer is busy, or your server is busy, or there are big pictures on the webpage, or it is a long webpage. While the webpage is loading, the browser symbol to the top right of the screen rotates, a message appears at the bottom of the screen, and the mouse pointer changes to an eggtimer. If you want to stop a slow webpage loading, click on the Stop button.

To log on to the internet means the same as to connect to the internet. But you can also log on to an email service, and the term crops up elsewhere. It means 'start something'. To stop something, you log off.

Macintosh computers are personal computers made by Apple. They are called Macs or iMacs. They have a different processing chip and operating system to PCs, so work in a subtly different way, although they do similar things. The internet is designed so webpages and emails will work on both Macs and PCs, in theory.

A mailing list enables members of a group to send emails to the whole group at the same time.

A mouse mat is a small mat that makes it easier to roll a mouse. A mouse tends to skid on a polished surface like a desk.

MB or megabyte is a million bytes.

Megahertz (MHz) measures the speed of a computer.

Computer memory is where the computer does its work when it is switched on. The speed of a computer and the size of its memory are the two main factors governing its cost. When buying a computer, make sure that it has enough memory to do what you want it to do (like using the internet). Memory is measured in bytes (usually megabytes or MB).

A message board is another word for bulletin board.

A mirror sites is a copy of a website. It may increase access to a very busy website, or spread knowledge of a website, or preserve a website that is being closed down.

A modem is a piece of hardware which lets your computer and your telephone talk to each other so you can be connected to the internet. The speed of a modem is measured in bps. A slow modem can slow down your use of the internet. However, there is no point in having a modem which works faster than the telephone line.

A moderated group has all its posted messages checked by someone before appearing. A moderated chatroom will be scrutinised by a responsible person.

A monitor is another word for a computer screen. You can buy them in different sizes, and if you have trouble reading the screen, you could consider getting a larger one.

A mouse lets you communicate with your computer. It has a ball underneath. As you roll it around on the table or mouse mat, a pointer moves around the screen. You click on a button on the top (left button for PCs; a Mac mouse only has one button) to choose the thing that you're pointing to. Click here for more on using the mouse.

Mozilla is the replacement for Netscape. It is a browser. You can download it. Look in the top left or top right of this screen, where you might see the symbols for Netscape (Mozilla symbol and Mozilla symbol). It uses similar terms and buttons as the other browser, Internet Explorer, except it says Bookmark rather than Favorite.

MP3 is a way of compressing music so it can be downloaded easier from the web. There are a lot of MP3 files on the web, but many are illegally breaching copyright.

A navigation bar directs you onto the second, and subsequent, pages of links listed by a search engine.

The net is short for the internet.

Netiquette defines acceptable behaviour in the interactive internet. If you don't follow it, you might get flamed.

Netscape has been replaced by Mozilla.

A network of computers is a number of computers connected together so they can share data and programs. The most famous network is, of course, the internet.

A newsgroup is like a discussion forum, but is NOT web-based. You will need newsreader software. Your ISP will tell you which newsgroups it supports.

Newsreader software is the software that you will need to use newsgroups.

Offline means logged off from the internet. Click here to find out more about working offline.

Online means logged on to the internet (and so possibly running up your telephone bill). You may be able to do some work offline.

An operating system is the software which makes the computer work. It handles the files, makes sure the various bits of hardware talk to each other, runs the different programs when you want them. Sometimes it crashes!

A page is short for a webpage.

A password is a word only known to you (you hope!) which you type in to confirm your identity or to access information private to you (such as emails). It appears on the screen as a row of asterisks (****) to prevent someone reading it over your shoulder.

PC stands for 'personal computer'. PCs contain a processing chip made by Intel, and an operating system by Microsoft. All PCs work in similar ways, but vary in speed and size.

A plugin is some software that you will need to do certain things on the internet, such as listen to music, or watch a film clip. Shockwave Flash and Adobe Acrobat are plugins. You may be given the opportunity to download the relevant software.

A mouse pointer is the symbol on the screen that represents the current position of the mouse.

To post a message means to put it on interactive internet, where it can be read by a group of people.

The Print button prints out the whole of a webpage. Click here for more about Print.

A printer is a piece of hardware which prints out things from your computer. There are different types of printers. If you buy a personal computer, then an inkjet printer is usually part of the package. A laser printer is a better (and more expensive) printer usually used for commercial computing.

The processing chip of a computer is the hardware that makes it work. All other hardware either stores data, or communicates with people or other computers.

A processor is another word for the processing chip. A word processor is a program for typing letters and so on.

Computer programs are collections of instructions which make a computer do something. They are sometimes called software. Word processors, paint programs, computer games, browsers are all types of programs.

RAM is another word for memory. It stands for Random Access Memory.

The Refresh button (which Netscape calls Reload) loads the current webpage again. You might want to do this, either because you think that the webpage might have changed, or because you've changed your mind after clicking on Stop.

A roller-ball is a way of communicating with your computer, similar to the mouse. It has a ball on top (rather than underneath) which you move with your finger. It is used more on laptop than desktop computers.

A scanner is a piece of hardware. It works a bit like a photocopier to convert pictures and text into a form that can by used in word processing, or on the internet.

A scroll bar on a webpage enables you to see the whole webpage. There is a scroll bar to the right of this creen. Click here to see how to use one.

Scrolling up or down means moving up or down a webpage. Occasionally, you may need to scroll left or right as well. Click here to see how to scroll.

A search engine is a website, which finds webpages about information that you're interested in, using a search key. Click here for how to use search engines. See site search.

Your server is the computer belonging to your ISP. Everything you do with the internet goes through your server. If your server is busy, then everything runs slow. Your server may also store your email until the next time you connect to the internet when it will download it. It may offer webspace for your own website.

Shockwave Flash is software which produces clever effects on some websites. Unfortunately if you don't already have the software, the clever effects won't work. You may be given the opportunity to download the software.

A site is short for a website.

A site search is a search engine which only examines webpages within a single website. Click here for more on site searches.

A site map is a webpage within a website which describes how that website is arranged. Click here for more on site maps.

Software is the computer programs that make a computer work. It includes the computer's operating system. See hardware.

A sound card is something inside the computer which makes sound (such as music or speech). It uses external speakers. A PC has its own internal speaker, which makes limited sound, but you will need a sound card and speakers for any good quality sound.

Spam is the email equivalent of junk mail. (It comes from the Monty Python Spam sketch.)

The speed of a computer is measured in megahertz (MHz). The faster a computer, the more it costs. A slow computer can be very frustrating to use.

A spider is a computer program used by search engines to find links to webpages.

The Stop button stops a webpage from loading. If you change your mind, and want to carry on loading it, click on the Refresh button.

Surfing the web means searching the world wide web, probably using a search engine or web directory.

A terminal is another word for a computer, particularly one connected to other computers, such as in the internet.

Text means letters, words and sentences, rather than pictures.

A thread is a collection of messages with the same subject heading within a discussion forum or newsgroup.

A touchpad fufils the same purpose as a mouse in a different way. It is used on laptop computers.

To unzip a file means to undo the zipping of the file so you can use it.

A URL is another name for a web address. It stands for Uniform Resource Locator.

A USB port is one type of socket on a computer. Many devices use USB ports.

A USB stick stores data. It fits into a USB port in the computer. You can save data from one computer onto a USB stick, and then take it to another computer to use the data.

Usenet is the collection of most (but not all) newsgroups.

A user id stands for 'user identifier'. Unlike the password, the user id can be read from the screen.

Video conferencing is a way of holding meetings via the internet. A video link lets you can see who you're talking to. The picture quality may be less than wonderful.

A virus is a program written by a malevolent person, which copies itself from one computer to another. It might damage the computer's software as well. Click here for more on viruses.

WAP phones are mobile phones which can be used for the internet. Obviously they can only look at very small webpages. WAP stands for Wireless Application Protocol.

The web is short for the world wide web.

A web address takes you to a particular webpage. It is found in the address box at the top of the screen. It probably begins with www. and has dots (.) and slashes (/) in. Don't confuse it with an email address. Click here to see how to use a web address.

Web-based means using the world wide web.

A webcam is a camera that regularly updates photographs on a webpage. So it works rather like very very slow film.

A webcast is a broadcast on a website. It may be a concert or an inteview.

A web directory is a website, which lists webpages about information arranged by category and sub-category. Click here for how to use web directories.

A webmaster is a person who looks after a website.

A webpage is a page that can be read if you're connected to the internet. Every webpage has its own web address. Click here for how to move around a webpage.

A website is a collection of webpages that have been created and linked together. The web address of a website is its homepage. A website may contain just one webpage, or a dozen, or hundreds!

Webspace is where webpages are stored. If you write a webpage, you will need to transfer it to webspace on a server before it is accessible via the internet.

A window is the box, headed with a blue bar, which shows you what is happening at the moment. You can have more than one window on your screen at the same time. In the internet, you sometimes get error windows, or adverts in little windows popping up. Click here for a very simple guide to windows.

The world wide web is millions of webpages, which can be read by anyone who is connected to the internet.

www stands for world wide web. Most web addresses start with www.

To zip a file means to compress it using special software, such as Winzip. You can download such software from the internet. To use a zipped file, you need to unzip it first.

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