Anti-virus software - A program that finds and removes viruses from a computer. (来源：http://www.EnglishCN.com)
Backup - A copy on floppy disk or tape of files on a PC's hard disk. A backup is used 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).
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 Netscape 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'.
DOS - Disk Operating System. The original system used for PCs. You type in commands instead of pointing and clicking.
Driver - A small program that tells a PC how a peripheral works.
Electronic mail (email, e-mail) - Messages sent from one computer to another. You can see email on the screen or print it out.
Floppy disk - A cheap, removable disk used for storing or transferring information. It is floppy (soft) because it is plastic. See hard disk.
Floppy drive - The device used to run a floppy disk (usually drive 'A'.)
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.
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.
Kb, Mb, Gb - Kilobytes, megabytes, gigabytes. Used to measure computer memory and storage.
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 need a modem to connect to the Internet, to send electronic mail and to fax.
OCR - Optical Character Recognition. OCR lets a PC read a fax or scanned image and convert it to actual lettering.
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.
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).