<P> A central processing unit ( CPU ) is the electronic circuitry within a computer that carries out the instructions of a computer program by performing the basic arithmetic , logical , control and input / output ( I / O ) operations specified by the instructions . The computer industry has used the term `` central processing unit '' at least since the early 1960s . Traditionally , the term `` CPU '' refers to a processor , more specifically to its processing unit and control unit ( CU ) , distinguishing these core elements of a computer from external components such as main memory and I / O circuitry . </P>
<P> A central processing unit ( CPU ) is the electronic circuitry within a computer that carries out the instructions of a computer program by performing the basic arithmetic , logical , control and input / output ( I / O ) operations specified by the instructions . The computer industry has used the term `` central processing unit '' at least since the early 1960s . Traditionally , the term `` CPU '' refers to a processor , more specifically to its processing unit and control unit ( CU ) , distinguishing these core elements of a computer from external components such as main memory and I / O circuitry . </P>
which component of a computer controls the entire system
which component of a computer controls the entire system
central processing unit ( CPU )
central processing unit ( CPU )