List and briefly define the main structural components of a computer.

The structure of a computer has four main components.

• Central processing unit (CPU): it controls the computer and does the data processing. It has the control unit, the ALU and the registers.
• Main memory: it stores the programs and data that the CPU is working on.
• Input/output (I/O): it moves data between the computer and the outside world, such as a keyboard, a disk or a display.
• System interconnection (system bus): it is the path that carries data, addresses and control signals between the CPU, the memory and the I/O.