What is Central Processing Unit (CPU)? Explain.

This is the main part of computer hardware that actually processes data according to the instructions it receives. It controls the flow of data by directing data to enter the system, places it into memory, retrieves it as needed and directs the output according to stored instructions. It has three main units:

• Arithmetic and Logic Unit (ALU) – It is responsible for performing all arithmetic computations such as addition, subtraction, division, multiplication and exponentiation. It also performs logical operations involving comparisons among variables and data items.
• Memory Unit – In this unit, data is stored before being actually processed. The data so stored is accessed and processed according to a set of instructions which are also stored in the memory.
• Control Unit – This unit is entrusted with the responsibility of controlling and coordinating the activities of all other units of the computer system. It reads instructions from memory, decodes them, sets up routing of data through internal circuitry, and determines the next instruction to be executed.