uniti processingthe process of performing operations on the data as per the instructions specified by the user (programmain aim of this is to transform data into information data and instructions are taken from the primary memory and are transferred to the arithmetic and logic unitwhich performs all sorts of calculations when the processing completesthe final result is transferred to the main memory outputis the process of giving the result of data processing to the outside world various output devices are monitorprinter etc controlling the function of managingcoordinatingand controlling all the components of the computer system is handled by the control unit the control unit decides the manner in which the instructions will be executed and the operations will be performed computer hardware the essential hardware components of computer are cpu (central processing unit memory / (input/outputdevices central processing unitcoordinates all computer operations performs arithmetic and logical operations on data cpu follows the instructions contained in computer program to determine which operations should be carried out and in what order the cpu can perform arithmetic operations such as additionsubtractionmultiplication and division the cpu can also compare the contents of two memory cells and make decisions based on the results of that comparison the circuitry of modern cpu is housed in single integrated circuit or chip an ic that is full cpu is called microprocessor cpu contains special high speed memory locations called registers control unit(cu)it is responsible for controlling the transfer of data and instructions among other units of computer it manages and coordinates all the units of the computer department of csevishnu institute of technology