What does CPU stand for: CPU (pronounced as separate letters) is the abbreviation for central processing unit.
Sometimes referred to simply as the central processor, but more commonly called processor, the CPU is the brains of the computer where most calculations take place. In terms of computing power, the CPU is the most important element of a computer system.
Central Processing Unit. Also known as a microprocessor, a CPU is the brains of a computer. To be more specific, a CPU fetches program instructions from RAM (input), interprets and processes it (execution) and then sends back the computed results so that the relevant components can carry out the instructions.