Definition:Is the abbreviation for central processing unit. Sometimes referred to simply as the central processor, but more commonly called processor, the CPU is the brains of the computer where most calculations take place.
Hard Drive
Definition:a high-capacity, self-contained storage device containing a read-write mechanism plus one or more hard disk, inside a sealed unit.also called hard disk drive.
ROM and RAM
Definition:Once data has been written onto a ROM chip, it cannot be removed and can only be read. Unlike main memory (RAM), ROM retains its contents even when the computer is turned off.ROM is referred to as being nonvolatile, whereas RAM is volatile
External Memory Device
Definition:External memory which is sometimes called backing store or secondary memory, allows the permanent storage of large quantities of data. Some method of magnetic recording on magnetic disks or tapes is most commonly used.