Computer storage

Computer storage, computer memory, and often casually memory refer to computer components, devices and recording media that retain digital data used for computing for some interval of time. Computer storage provides one of the core functions of the modern computer, that of information retention. It is one of the fundamental components of all modern computers, and coupled with a central processing unit (CPU), implements the basic Von Neumann computer model used since the 1940s.

In contemporary usage, memory usually refers to a form of solid state storage known as random access memory (RAM) and sometimes other forms of fast but temporary storage. Similarly, storage more commonly refers to mass storage - optical discs, forms of magnetic storage like hard disks, and other types of storage which are slower than RAM, but of a more permanent nature. These contemporary distinctions are helpful, because they are also fundamental to the architecture of computers in general. As well, they reflect an important and significant technical difference between memory and mass storage devices, which has been blurred by the historical usage of the terms "main storage" (and sometimes "primary storage") for random access memory, and "secondary storage" for mass storage devices. This is explained in the following sections, in which the traditional "storage" terms are used as sub-headings for convenience.