The speed of CPU is extremely high compared to the access time of main memory. Therefore the performance of CPU decreases due to the slow speed of main memory. To decrease the mismatch in operating speed, a small memory chip is attached between CPU and Main memory whose access time is very close to the processing speed of CPU. It is called CACHE memory. It acts as a buffer between the CPU and Main memory. CACHE memories are accessed much faster than conventional RAM. It is used to store programs or data currently being executed or temporary data frequently used by the CPU. So cache memory “makes main memory to be faster and larger than it really is”. It is also very expensive to have bigger size of cache memory and its size is normally kept small.
Advantages:
1. Cache memory is faster than main memory.
2. It consumes less access time as compared to main memory.
3. It stores the program that can be executed within a short period of time.
4. It stores data for temporary use.
Disadvantages:
1. Cache memory has limited capacity.
2. It is very expensive.
