A computer monitor is an electronic device that shows pictures for computers. Monitors often look similar to televisions. The main difference between a monitor and a television is that a monitor does not have a television tuner to change channels. Monitors often have higher display resolution than televisions. A high display resolution makes it easier to see smaller letters and fine graphics.
There are three types of computer displays:
The CRT monitor. These are big and heavy and use a lot of desk space and electricity. It is the oldest technology used by monitors and is based on the cathode ray tube technology that was developed for television. Monitors are made with better parts which give a higher display resolution and picture sharpness than a television. This type of monitor is no longer popular.
The LCD monitor, the most common kind of flat panel display. It is a newer technology than CRT. LCD monitors use much less desk space, are lightweight and use less electricity than CRT. They have been used for many years in the screens of laptop and notebook computers. They also work as touch screens in tablet computers, mobile phones, and other handheld technologies.[1]
An LED Monitor (short for Light Emitting Diode) or LED display is an LCD Monitor that uses light emitting diodes for back lighting. The first LCD Monitors used cold cathode fluorescent lamps instead of LEDs to illuminate the screen.
In the early 21st century the price of video projectors has fallen and they are now used in many places to show large images. These use various technologies to make the image including LCD - Liquid crystal display and DLP - Digital light processing which uses very small mirrors to direct the light.