A computer consists of A central processing unit,memory and Input and Output unit.
The Central Processing Unit (CPU) The computer does its primary work in a part of the machine we cannot see, a control center that converts data input to information output. As Figure 1 shows, the central processing unit consists of two parts: The control unit and the arithmetic/logic unit.
The computer memory is a temporary storage area. It holds the data and instructions that the Central Processing Unit (CPU) needs. Before a program can be run, the program is loaded from some storage medium into the memory. This allows the CPU direct access to the program.