A cache memory works on the principle of locality of reference, a term for the phenomenon in which the same values, or related storage locations, are frequently accessed, depending on the memory access pattern. Caching improves access time and reduces data traffic to data sources that have limited throughput.
cache memory is much smaller than main memory. Consequently, it has less storage space. It is also more expensive than main memory, as it is a more complex chip that yields higher performance.
What it sacrifices in size and price, it makes up for in speed. Cache memory operates between 10 to 100 times faster than RAM, requiring only a few nanoseconds to respond to a CPU request.