Functional components of a computer system:
1. Input devices
They enter program and data into the computer system. Examples are keyboard, mouse, bar code reader, light pen, etc
2. Central Processing Unit (CPU)
This is the part of the computer that processes data. It consists of the main memory, the control unit and the arithmetic and logic unit.
3. Main memory
This is a temporary storage to hold programs and data during execution/processing.
4. Control unit
This controls the execution of programs.
5. Output devices
They display information processed the computer system. Examples are Monitors, printer, overhead projectors, etc
6. Storage devices
They provide permanent storage of data and programs before and after if is processed the computer system. Examples are hard disks, magnetic tape drives, optical disks, etc
7. Communication devices
They enable communication with other computers. Examples are modems, multiplexors, front-end processors, etc