Processor register

In computer architecture, a processor register (or general purpose register) is a small amount of storage available on the CPU whose contents can be accessed more quickly than storage available elsewhere. Typically, this specialized storage is not considered part of the normal memory range for the machine. Most, but not all, modern computers adopt the so-called load-store architecture. Under this paradigm, data is loaded from some larger memory — be it cache or RAM — into registers, manipulated or tested in some way (using machine instructions for arithmetic/logic/comparison) and then stored back into memory, possibly at some different location. A common property of computer programs is locality of reference: the same values are often accessed repeatedly; and holding these frequently used values in registers improves program execution performance.