One of the most important peripherals in computer is the graphic display device (Monitor). Conventional computer display terminals knows as alphanumeric terminal, display character (images) from a multi-dot array. These are used to read text information display of graphics, diagrams and pictures to make the visual presentation of information more effective for user interaction and decision making.

Graphic display is made up of a series of dots called 'pixels' (picture elements) whose pattern produces the images. Each dot on the screen is defined as a separate unit which can be directly addressed. Since each dot can be controlled individually there is much greater flexibility in drawing pictures.