Information Technology

Central Processing Unit and its Components

Central Processing Unit

Central Processing Unit

Central Processing Unit is the central part of the computer. It is also called the brain of the computer. It performs all operation according to the program instruction. Hence the Arithmetic & Logic Unit and Control Unit of the computer are both know as CPU. As a human body, all function and decision are taken by the brain. Other parts of the body are performed their function under the brain’s directions. Similarly all decision, operation, calculation and comparison are directly under the Central Processing Unit. CPU is the totally responsible of controlling and executing all operation of the commuter system. CPU consist of two parts like CU and ALU


CU is the central part of the processor that controls all the operation in computer system. CU establishes co-ordination among the ALU, Memory unit and other parts of the computer system. It also issue signal to computer system for execute the instruction which given to the computer. It fetch the program instruction from the main memory, decodes the program instruction, execute it and control give to the next instruction for execution. CU also acts upon as nervous system for the other parts of the commuter. It manages, controlled and coordinate entire computer system. It is not actually perform any process on data.


The automatic & logic unit is main component of the computer system where actual execution of the instruction during the processing. So entire calculation and decision performed in ALU. Prior to processing, the data and instruction are store in the main memory and then transferred to the ALU when needed it for processing. In primary memory processing not done. Arithmetic & logic unit consist of two parts. 

Arithmetic Section

This section of the ALU done arithmetic operation like addition subtraction multiplication and division

Logics section

Logic section of ALU did logic operation. In logic operation data are compared with other data e.g. withier the number is less then, greater then, equal to or not equal to another number