Cache memory is normally used between RAM and CPU. It has very low storage capacity as compared to the main memory or RAM. It is similar to RAM but it is extremely fast than RAM. Cache memory plays very important role in increasing the performance of a computer system. It speed up the processing speed of computer because CPU stores frequently used instructions and data in it. When the program is running and CPU needs a specific data or program instruction, CPU first looks it in cache memory. If the required data or instruction is found in cache memory, CPU reads the data or instruction from it. So the working of CPU is increased.