What is cache memory ? How is it useful ?

The cache memory is a high speed memory available inside CPU in order to speed up access to data and instructions stored in RAM memory. Whenever some data is required, the CPU first looks in the cache, if it is there or not. If the data is found in cache, CPU does not access memory and hence the process becomes very fast.

Memory caching is effective because most programs access the same data or instructions over and over. By keeping as much of this information as possible in cache memory (SRAM), the computer avoids accessing the slower main memory (DRAM). Hence, cache memory is useful for improving the performance of the computer.