A central processing unit, also called a central processor, main processor or just processor, is the electronic circuitry within a computer that executes instructions that make up a computer program.
Electronic circuitry within a computer that carries out the instructions of a computer program by performing the basic arithmetic, logical, control and input/output operations specified by the instructions
The central component in a computer that interprets program instructions and processes data.
The part of a computer that fetches, decodes and executes instructions; attached directly to the memory. Abbreviated: CPU.