Random Acces Memory ( RAM )

RAM ( Random access memory ) was usually used in CPU as data storage of computer. Today it takes the form of integrated circuits that allow the stored data to be accessed in any order, i.e. at random. The word random thus refers to the fact that any piece of data can be returned in a constant time, regardless of its physical location and whether or not it is related to the previous piece of data.This contrasts with storage mechanisms such as tapes, magnetic discs and optical discs, which rely on the physical movement of the recording medium or a reading head. In these devices, the movement takes longer than the data transfer, and the retrieval time varies depending on the physical location of the next item. Some ramdisks use a compressed filesystem such as cramfs to allow compressed data to be accessed on the fly, without uncompressing it first. This is convenient because ramdisks are often small due to the higher price per megabyte than conventional hard drive storage.