computer storage

Information and documents are stored in computer storage so that it can be retrieved whenever they are needed later on.
Primary storage is known as the main memory of a computer, including RAM (Random-Access Memory) and ROM (Read-Only Memory). It is an internal memory (inside the CPU) that can be accessed directly by the processor. Primary storage is installed internally. Two main types of primary storage are RAM and ROM.Data from RAM can be read or retrieved and written or stored during processing whereas data from ROM can just be read only.RAM is volatile, which means the program and data will be lost when the computer is turned off.
ROM is non-volatile which means it holds the programs and data even when the computer is turned off.
Secondary storage is the alternative storage in a computer. It is an external storage that refers to various ways a computer can store program and data.
Secondary storage is an alternative storage. It is very useful to store programs and data for future use. Secondary storage is required for two reasons.
The working memory of the CPU is limited in size and cannot always hold the amount of data required.
Data and programs in secondary storage do not disappear when the power is turned off.

http://search.yahoo.com/search;_ylt=A0oGkmTe.MZHfQEB9_9XNyoA?phttp://search.yahoo.com/search;_ylt=A0oGklZ2.cZHlSAAqPxXNyoA?p