Central Processing Unit (CPU)
     CPU is one of the major component of computer system which is responsible for controlling all the other components of the computer system. The CPU of a computer system is a piece of hardware that carries out the instructions of a computer program. It handles all the instruction given to the computer system. It performed the basic arithmetic and logical and the input output operation of the computer system. CPU is also referred as processor. In now a days it is also known as microprocessor. CPUs are located on the motherboard. Motherboard have socket for this which is specific for a certain type of processor. A CPU gets very hot so it need on cooling system in the form of heat sink or a fan.

                              microprocessor
      The important feature of CPU are given below:-

• it stores data Intermediate result and the instruction as well. 
• it is considered as the brain of computer system. 
• it performs all types of data processing operation. 
• it controls the operation of all parts of the computer.

 CPU has the major two units :-

1. Arithmetic logic unit (ALU):-  ALU is responsible for performing an arithmetical and logical operations. This unit consists of two subsections namely arithmetic section and logic section.
2. control unit:-  This unit controls the operation of all parts of the computer but does not carry out any actual data processing operations. The functions of control unit are given below:-

• it is responsible for controlling the transfer of data and instruction among other units of a computer.
•  it obtains the instruction from the memory integrated them and directs the operation of the computer.
•  it is responsible for controlling the communication of input output unit. it communicate with input output device for transfer of data or result.
•  It manages and coordinates all the units of the computer.