<
storage> (Or cache block) The smallest unit of memory than can be transferred between the
main memory and the
cache.
Rather than reading a single word or byte from main memory at a time, each cache entry is usually holds a certain number of words, known as a "cache line" or "cache block" and a whole line is read and cached at once. This takes advantage of the principle of locality of reference: if one location is read then nearby locations (particularly following locations) are likely to be read soon afterward. It can also take advantage of page-mode
DRAM which allows faster access to consecutive locations.