Cache memory
Cache memory is a high-speed memory region (compared to the speed of main memory) that temporarily stores program instructions or data for future use. Usually, these instructions or data items have been retrieved from main memory recently and are likely to be needed again shortly.
The primary purpose of cache memory is to increase the speed of repeatedly accessing the same memory location and nearby memory locations. To be effective, accessing the cached items must be significantly faster than accessing the original source of the instructions or data, referred to as the backing store.
When caching is in use, each attempt to access a memory location begins with a search of the cache. If the requested item is present, the processor retrieves and uses it immediately. This is called a cache hit. If the cache search is unsuccessful (a cache miss), the instruction or data item must be retrieved from the backing store. In the process of retrieving the requested item...