Cache is generated when program instructions and data that are used frequently in the operation of the programs are stored in the CPU memory. The CPU memory is designed to be integrated directly to the CPU Chip or as close as possible to it. This allows a computer microprocessor the ability to access it more quickly than it can access the regular random access memory (RAM) which is much slower. Because the computer processor can access this information much quicker from the cache, it can ignore the slower main memory unless when necessary; this process ultimately increases the overall speed of your Mac.