Parts of computer

A computer divides into five elements:
Arithmetic and logic subsystem,
control subsystem,
main storage,
input subsystem, and
output subsystem.


These are the parts :

* processor
* arithmetic and logic
* control
* main storage
* external storage
* input
* output


Processor
The processor is the part of the computer that actually does the computations. This is sometimes called an MPU (for main processor unit) or CPU (for central processing unit or central processor unit).


Arithmetic and Logic

An arithmetic/logic unit (ALU) performs integer arithmetic and logic operations. It also performs shift and rotate operations and other specialized operations. Usually floating point arithmetic is performed by a dedicated floating point unit (FPU), which may be implemented as a co-processor.



control

Control units are in charge of the computer. Control units fetch and decode machine instructions. Control units may also control some external devices.



main storage

Main storage is also called memory or internal memory (to distinguish from external memory, such as hard drives).


external storage

External storage (also called auxillary storage) is any storage other than main memory.



input/output overview

Most external devices are capable of both input and output (I/O). Some devices are inherently input-only (also called read-only) or inherently output-only (also called write-only). Regardless of whether a device is I/O, read-only, or write-only, external devices can be classified as block or character devices.



input
Input devices are devices that bring information into a computer.



output

Output devices are devices that bring information out of a computer.