Cache memory is used to increase the performance of the PC. It holds data and instructions retrieved from RAM to provide faster access to the CPU.
As a computer system is built using components from different suppliers, there are no standards on the speeds and transfer rates of these components. The CPU (processor) and main memory (RAM) overcome these differences by using cache memory.
Cache memory is an extremely fast memory type that acts as a buffer between RAM and the CPU. It holds frequently requested data and instructions so that they are immediately available to the CPU when needed.
Cache memory is located in two general locations: inside the processor (internal cache) and on the motherboard (external cache):
Internal cache: also known as primary cache, internal cache is located inside the CPU chip.
External cache: also known as secondary cache, external cache is located on the motherboard outside the CPU. This is the cache referred to on PC specifications.