Function of the CPU

CPU stands for central processing unit. Overall a personal computer can be divided into the following major parts from point of view of functions performed:

1. Input devices (keyboard, mouse)
2. Output devices (monitor which displays the output or results of work being done on the computer)
3. CPU (central processing unit, which is the brain of the computer which does all the processing and calculations on data inputs and provides output on screen or printer)
4. Storage devices (memories, hard disk which store data).

Many times in common language the CPU term is used for the computer box unit which contains motherboard, processor, hard disk, CD/DVD and floppy drives. This is the box to which we connect monitor, keyboard, mouse and printer through cables. In technical terms the term CPU is used only for the processor, which fits on the motherboard.
Central Processing Unit (CPU), in computer science, microscopic circuitry that serves as the main information processor in a computer. A CPU is generally a single microprocessor made from a wafer of semiconducting material, usually silicon, with millions of electrical components on its surface. On a higher level, the CPU is actually a number of interconnected processing units that are each responsible for one aspect of the CPU's function. Standard CPUs contain processing units that interpret and implement software instructions, perform calculations and comparisons, make logical decisions (determining if a statement is true or false based on the rules of Boolean algebra), temporarily store information for use by another of the CPU's processing units, keep track of the current step in the execution of the program, and allow the CPU to communicate with the rest of the computer.