A peripheral device is any hardware devices that are connected to a computer system unit in order to make the computer easier to use or to extend the computer capabilities.
what is peripheral divice

Peripheral devices provide input to or accept output from the computer. in other words, A peripheral device is a hardware used for input-output auxiliary storage.
Example of such device includes monitor, printers, scanner,keybord, speaker, mouse, floppy diskettes, joystick, OCR (optical character reader) voice recognition device and graphic table.
In summary, we can grouped peripheral devices under.

   - INPUT/OUTPUT {I/ O}:-  Refers to the communication between an information processing system "such as a computer and the outside world possibly a human or other information processing system.

Inputs are the signal or data received by the system or data sent from between an information processing system (such as a computer)
and the outside world possibly a human or another information processing system.
Input are the signal of data recieved by the system and the outputs are the signal or data sent from it.

Devices that provide input or output to the computer are called peripherals.

 On a typical personal computer, peripheral include input devices like the keybord and mouse and output devices such as display abd printer, Hard disk drives, floppy disk drives and optical dics drives serve as both input and output devices computer networking is another From I/O.


What is processing components.

Processing components is a responsible for processing or manipulation od data to yeild the desired result. That portion of the computer system unit where most activities take place
is referred to as the central processing unit  CPU  subsystem.

All peripheral devices such as monitor and keybord are connected to , and controlled  by this subsystem.

The device component that carried out this processing operation in a small computer is called "microprocessor"
Microprocessor is situated on an electronic circut board  popularly known as motherbord or main board.
On many larger computers, the processing is carried out by a number of separate chips (ICs) , insteade of single IC  as the case of microprocessor.

A computer whose  processing is done by a microprocessor is called a "microcomputer".