Cache (computing)
Typical computer applications access data in very similar ways. Suppose the data is structured into "blocks", which can be accessed individually. When an application accesses a block it is also very likely to access (or reference) a block that is "close" to the original block. This is known as locality of reference. There are different kinds of such "locality".  Locality of reference is one of the reasons why caches work well in many areas of computing.