| cache memory
also called CACHE, a supplementary
memory system that temporarily stores frequently used
instructions and data for quicker processing by the
central processor of a computer. The cache
augments, and is an extension of, a computer's
main memory. Both main memory and cache are internal,
random-access memories (RAMs) that use
semiconductor-based transistor circuits. Cache holds a
copy of only the most frequently used information or
program codes stored in the main memory; the smaller
capacity of the cache reduces the time required to
locate data within it and provide it to the computer
for processing.
When a computer's central processor accesses
its internal memory, it first checks to see if the
information it needs is stored in the cache. If it is,
the cache returns the data to the processor. If the
information is not in the cache, the processor retrieves
it from the main memory. Disk cache memory operates
similarly, but the cache is used to hold data that has
been recently written on, or retrieved from, a magnetic
disk or other external storage device.
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