The monitor is a part of computer hardware that displays video and graphic information as output generated by the computer through the video card. Computer monitors are very much similar to that of television screens but they display video at the higher resolution. Unlike the televisions which are mounted on a wall, the computer monitors are fixed on top of a desk. The computer monitors are also named as video screen, video display, video display terminal or video display unit. It is not the same that turning off the computer is turning off the monitor. Generally, monitors are not typically user serviceable.
CRT in full form is a Cathode Ray Tube monitor which is based on older technology. Almost all of the older monitors are based on cathode ray technology. The cathode is basically a negatively charged electrode that shoots a beam of electrons to a positively charged electrode which is known as the anode. The cathode ray tube is mainly a vacuum tube which is having more than one number of electron guns or cathodes at one end and which shoots electrons at a monitor at the other end. The inside of the screen is mixed with dots, which is made up of phosphorescent material.
LCD monitor in full form is named as liquid crystal display monitor. An LCD monitor uses a layer of liquid crystal material placed in between two grids of electrodes, one arranged in rows and the other in the columns. These grids are enclosed with a layer of polarizing material made with plastic or glass. These polarizing layers are aligned to avoid light passing through these layers if the electrodes are not activated. This process is done only by the manipulation of electronic grids. The LCD monitors mostly used today are used with TFT (Transistor film technology), in which a transistor is placed at the intersection of electronic grids to enhance the signal and as well as picture quality. This is also known as matrix display.
In the previous decade, the technology has changed drastically. LED displays are one of the largest developments in this area. LED monitors use light emitting diodes that act as performance boosters in the monitors. Basically LED displays are LCD displays with LED backlight to power up the LCD panel. This means that LED'S are placed behind or around the LCD panel. There are three different types of LED models are there, they are Direct LED'S, Edge LED, and RGB LED'S. The both edge and direct LED's use white diodes that are used to illuminate LCD panel to improve picture quality.
The old model CRT type of computer monitors are lesser in price and quality is good in those days, but the LCD monitors are much costlier than that of CRT monitors.
In the beginning, the LCD monitors are much costlier and quality is very low, but now quality is also increased with the price.
LED monitors are much more costly than CRT and LCD monitors.
So, buy monitors depending upon low price and good quality.