anti-virus software - a program that finds and removes viruses from a computer
app - a self-contained program or piece of software; an application, especially when downloadable to a mobile device
application - a self-contained program or piece of software
backup - a copy of files from a computer's hard disk, usually made on some external medium such as CD-ROM or flash drive. A backup is made in case the hard disk file(s) are erased or damaged.
bit, bytes - a bit is the smallest piece of information that computers use. For simplicity, a PC uses bits in groups of 8 called bytes (8 bits = 1 byte).
Bluetooth - a way of communicating wirelessly over short distances between electronic devices (for example computer and mobile telephone)
boot, boot up, boot disk - You boot (or boot up) your computer when you switch it on and wait while it prepares itself. Instructions for startup are given to the computer from the boot disk, which is usually the hard disk.
browser, to browse - A browser is a program like Firefox or Internet Explorer. You use it to view or browse the Internet.
bug - a (small) defect or fault in a program
cache - a kind of memory used to make a computer work faster
CD-ROM - a disk for storing computer information. It looks like an audio CD.
CPU - Central Processing Unit. This is a PC's heart or "brains".
data - Usually means the information (text, pictures, audio etc) that you create or share on a computer, as opposed to the programs that manipulate the data.
DOS - Disk Operating System. The original system used for PCs, where you typed in commands instead of pointing and clicking.
driver - a small program that tells a PC how a peripheral works
ebook - an electronic book that can be downloaded and read on a computer or other device
electronic mail (email, e-mail) - messages sent from one computer to another. You can see email on the screen or print it out.
file - a specific computer record. It could contain data such as text (eg essay.doc), or a program such as paint.exe.
floppy disk - a cheap, removable disk used for storing or transferring information. It is floppy (soft) because it is plastic. (Now virtually obsolete.) See hard disk.
floppy drive - The device used to run a floppy disk (usually drive "A".) (Now virtually obsolete.)
folder (directory) - a sub-division of a computer's hard disk into which you put files
font - a particular sort of lettering (on the screen or on paper). Arial is a font. Times New Roman is another.
format - All hard disks and floppy disks have to be electronically prepared for use by a process called formatting. Hard disks are pre-formatted by the computer manufacturer. If you buy a floppy disk that is not pre-formatted, you format it yourself, using a program that comes with your PC.
graphics card - the equipment inside a computer that creates the image on the screen
hard disk - the main disk inside a computer used for storing programs and information. It is hard because it is metal. See floppy disk.
hotspot - an area that has an available wireless signal for Internet access (usually public)
icon - a small image or picture on a computer screen that is a symbol for folders, disks, peripherals, programs etc
Internet - International network of computers that you connect to by telephone line. Two popular services of the Internet are the World Wide Web and electronic mail.
iPad - a tablet computer created by Apple.
Kb, Mb, Gb - kilobytes, megabytes, gigabytes. Used to measure computer memory and storage.
Kindle - a device for downloading and reading ebooks, developed by Amazon.com.
memory - Memory is for the temporary storing of information while a computer is being used. See RAM, ROM and cache.
MHz - Megahertz. This describes the speed of computer equipment. The higher the MHz the better the performance.
modem - equipment connected to a computer for sending/receiving digital information by telephone line. You may need a modem to connect to the Internet, to send electronic mail and to fax.
notebook - a notebook computer; a laptop computer; a folding, portable computer.
operating system (OS) - the basic software that manages a computer (for example, Windows 10, OS X, Unix, iOS).
OCR - Optical Character Recognition. OCR lets a PC read a fax or scanned image and convert it to actual lettering.
palmtop - a computer that is small enough to sit on the palm of the hand
parallel port - a socket at the back of a computer for connecting external equipment or peripherals, especially printers
PC card - a device that is the same size as a thick credit card, for plugging into a slot on notebook computers. You can buy memory, modems and hard disks as PC cards.
PDA - abbreviation of "personal digital assistant"
peripheral - any equipment that is connected externally to a computer. For example, printers, scanners and modems are peripherals.
pixel - the image that you see on the screen is made of thousands of tiny dots, points or pixels
program software that operates a PC and does various things, such as writing text (word-processing program), keeping accounts (accounts program) and drawing pictures (graphics program)
QWERTY - The first 6 letters on English-language keyboards are Q-W-E-R-T-Y. The first 6 letters on French-language keyboards are A-Z-E-R-T-Y.
RAM, ROM - two types of memory. RAM (Random Access Memory) is the main memory used while the PC is working. RAM is temporary. ROM (Read Only Memory) is for information needed by the PC and cannot be changed.
resolution - the number of dots or pixels per inch (sometimes per centimetre) used to create the screen image
scanner - equipment for converting paper documents to electronic documents that can be used by a computer
serial port - socket at the back of a PC for connecting peripherals (obsolescent)
smartphone - a mobile phone that includes a palmtop computer or PDA and also gives access to Internet and email
tablet - a tablet computer; a mobile computer consisting of a screen only, and controlled by touching the screen
TFT - Thin Film Transistor, a type of high quality screen for notebook computers
USB - abbreviation of "universal serial bus"; a standardized connection for attaching devices to computers etc
USB flash drive - a small, external device for storing data; it connects through the USB socket.
virus - a small, unauthorized program that can damage a computer
Wi-Fi - a system for communicating without wires over a computer network
Windows - an operating system used by the majority of PCs
World Wide Web, WWW, the Web - WWW are initials that stand for World Wide Web. The Web is one of the services available on the Internet. It lets you access millions of pages through a system of links. Because it is "world-wide", it was originally called the World Wide Web or WWW.
WYSIWIG - "What You See Is What You Get." With a WYSIWIG program, if you print a document it looks the same on paper as it looks on the screen.