The CPU, or the Central Processing Unit, is the brain of the computer and the single most important chip in the computer. Modern processors contain millions of transistors which are etched onto a tiny square silicon called a die, which is about the with of a standard thumb. The CPU performs the system's calculating and processing.

The majority of personal computers include the Intel processors.

Intel released the first processor, the 4004, in 1970. Today, the market is being shared by other companies such as the popular AMD processor manufactured by the AMD company.