Central Processing Unit

The Central Processing Unit is the part of the computer that processes instructions from the data instructions that it retrieves from RAM. The computer then sends the results back to RAM to be stored or delivered to output. The CPU is thought of as the "brain" of the computer. The CPU takes care of the information, and dumps it onto the bus (circuits that that provide the electronic roadway for the information processed by the CPU).

The Central Processing Unit (CPU) performs the actual processing of data. The data it processes is obtained, via the system bus, from the main memory. Results from the CPU are then sent back to main memory via the system bus. In addition to computation the CPU controls and co-ordinates the operation of the other major components.

The CPU speed is influenced by clock rate, word size, cache and instruction set size. Computers can have a highly rated processor but if it has a slow hard drive or small amount of RAM it still may be slow.

Arithmetic Logic Unit carries out arithmetic operations on integer (whole number) and real (with a decimal point) operands. It can also perform simple logical tests for equality and greater than and less than between operands. Control Unit controls the fetching of instructions from the main memory and the subsequent execution of these instructions. Among other tasks carried out are the control of input and output devices and the passing of data to the Arithmetic/Logical Unit for computation. Memory Unit is the part of computer that holds data and instructions for processing. Memory associated with the CPU is also called as Primary storage or Primary memory.