Special high-speed memory area on a chip that the CPU can access quickly.
A copy of the most frequently used instruction is kept in the cache memory
so the CPU can look there first.

Cache memory is random access memory (RAM) that a computer microprocessor can access more quickly than it can access regular RAM. As the microprocessor processes data, it looks first in the cache memory and if it finds the data there (from a previous reading of data), it does not have to do the more time-consuming reading of data from larger memory .