A computer uses two types of storage. A main store consisting of ROM and RAM, and backing stores which can be internal, eg hard disk, or external, eg a CD or USB flash drive.
ROM and RAM
Main store (or computer memory) is divided into Read Only Memory (ROM) and Random Access Memory (RAM).
ROM is memory that cannot be changed by a program or user. ROM retains its memory even after the computer is turned off. For example, ROM stores the instructions for the computer to start up when it is turned on again.
RAM is a fast temporary type of memory in which programs, applications anddata are stored. Here are some examples of what's stored in RAM:
- the operating system
- the graphical user interface (GUI)
If a computer loses power, all data stored in its RAM is lost.