Monitor is the output device which is connected with the CPU. The data and instructions being given to the computer are displayed on the monitor. It is also called Visual Display Unit (VDU). It is like a TV screen which displays the characters and it has a cathode ray tube (CRT).

All monitors are not of same type. There are various types of monitors classified on the basis of resolution and size. Monitors have small, medium and large resolution depending on the size. The monitors need an interface card to control and send data from the CPU.