A technique to minimize time spent waiting for some needed data to arrive, effectively hiding the latency of the fetch or part of it. Examples include instruction and data prefetching in microprocessors, and link prefetching in html browsers.
Prefetching is a technique to minimize time spent waiting for some needed data to arrive, either externally by the user or internally by the system. If the target of the request (whether a memory address, or a web link) can be predicted well enough in advance, a prefetch dispatched early will have time to fetch the data before the actual demand, thereby hiding the latency of the demand itself when it arrives. As the prefetch may arrive even earlier than needed, prefetching is often associated with caching mechanisms. Examples include instruction and data prefetching in microprocessors (both software based and hardware prefeching), link prefetching in html browsers, and database prefetching mechanisms.
