backup - A copy of files from a computer's hard disk. A backup is made in case the hard disk files are erased or damaged.
Bluetooth - a way of communicating wirelessly over short distances between electronic devices (for example computer and mobile telephone)
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.
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.
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 (eg paint.exe).
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.
format - All hard disks have to be electronically prepared for use by a process called formatting. Hard disks are pre-formatted by the computer manufacturer.
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.
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.
Kb, Mb, Gb - kilobytes, megabytes, gigabytes. Used to measure computer memory and storage.
MHz - Megahertz. This describes the speed of computer equipment. The higher the MHz the better the performance.
operating system (OS) - The basic software that manages a computer (for example, Windows 7, OS X, Unix, iOS).
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.
peripheral - Any equipment that is connected externally to a computer. For example, printers, scanners and modems are peripherals.
RAM, ROM - Two types of memory: (Random Access Memory) is the main memory used while the PC is working,it is temporary. Read Only Memory is the information needed by the PC and cannot be changed.
scanner - Equipment for converting paper documents to electronic documents that can be used by a computer.
tablet - a tablet computer; a mobile computer consisting of a screen only, and controlled by touching the screen.
USB - abbreviation of "universal serial bus"; a standardized connection for attaching devices to computers etc.
virus - A small, unauthorized program that can damage a PC.
Wi-Fi - a system for communicating without wires over a computer network.
World Wide Web, WWW, the Web - The Web is one of the services available on the Internet. It lets you access millions of pages through a system of links.