A microprocessor is the main part of all communication networks, computers, and most workstations. It is the brains of the system. Sometimes referred to simply as the central processing unit (CPU), the microprocessor is where most operations take place. In terms of computing power, the CPU is the most important element of a system. On large machines, microprocessors require one or more printed circuit boards. On personal computers and small workstations, the microprocessor is housed on a single chip. Microprocessors also control the logic of almost all digital devices, from clock radios to fuel-injection systems for automobiles.