The full form of CPU is Central Processing Unit. It is the main part of a computer and is often referred to as the brain of the computer. The CPU carries out instructions and computer programs and performs all the basic arithmetical and logical operations. The term CPU is normally used to refer to a processor that consists of the arithmetical logical unit and control unit. The three main components of the CPU are:

• Arithmetic Logic Unit (ALU): This is responsible for performing all the logical and arithmetical operations. It is a significant part of the CPU and is responsible for all numerical and logical functions.

• Control Unit (CU): This is the main component of the CPU and directs the operations of the processor. It selects and retrieves instructions from the main memory in proper sequence and interprets them so as to activate the other functional elements of the system at the appropriate moment to perform their respective operations.

• Registers: These are high-speed memory units that are utilized to store data during processing.

The CPU is mounted on the motherboard in a specific space known as the CPU socket. Traditionally, the term CPU refers to a processor that includes a control unit and an arithmetic logical unit.