Cache is integrated into the CPU and used as storage support for CPU operations. Because of the CPU chip area and cost, the cache is very small. The cache is usually only a few MB. The operation frequency of the cache in the CPU is extremely high. It is generally the same as that of the processor, and the working efficiency is far greater than the system memory and hard disk. In actual work, the CPU often needs to read the same data block repeatedly, and the increasing cache capacity can greatly improve the data read hit rate inside the CPU, instead of searching for data in the memory or hard disk, to improve system performance. The memory is used as the storage support between the CPU and the hard disk. Plug in the memory slot of the motherboard. The current memory is generally 1 ~ 2G. That is, 1g = 1024m, which is a bridge to communicate with the CPU. All programs in the computer run in the memory, so the memory performance has a great impact on the computer. Memory (memory) is also called internal memory. It is used to temporarily store computing data in the CPU and data exchanged with external memory such as the hard disk. As long as the computer is running, the CPU transfers the data to be computed to the memory for computation. After the computation is completed, the CPU sends the result, the memory operation also determines the computer's stable operation.