A monitor or display (sometimes called a visual display unit) is an electronic visual display for computers. The monitor comprises the display device, circuitry, and an enclosure. The display device in modern monitors is typically a thin film transistor liquid crystal display (TFT-LCD) thin panel, while older monitors use a cathode ray tube (CRT), typically about as deep as the screen size.

Originally computer monitors were used for data processing and television receivers for entertainment; increasingly computers are being used both for data processing and entertainment. Displays exclusively for data use tend to have an aspect ratio of 4:3; those used also (or solely) for entertainment are usually 16:9 widescreen, Sometimes a compromise is used, e.g. 16:10.

Comparison

CRT

   Pros:

• High dynamic range (up to around 15,000:1), excellent color, wide gamut and low black level.

• Can display natively in almost any resolution and refresh rate

• No input lag

• Sub-millisecond response times

• Near zero color, saturation, contrast or brightness distortion. Excellent viewing angle.

• Usually much cheaper than LCD or Plasma screens.

   Cons:

• Large size and weight, especially for bigger screens (a 20-inch unit weighs about 50 lb (23 kg))

• High power consumption

• Geometric distortion caused by variable beam travel distances

• Older CRTs are prone to screen burn-in

• Produces noticeable flicker at low refresh rates

LCD

   Pros:

• Very compact and light

• Low power consumption

• No geometric distortion

• Rugged

• Little or no flicker depending on backlight technology

   Cons:

• Limited viewing angle, causing color, saturation, contrast and brightness to vary, even within the intended viewing angle, by variations in posture.

• Bleeding and uneven backlighting in some monitors, causing brightness distortion, especially toward the edges.

• Slow response times, which cause smearing and ghosting artifacts. Modern LCDs have response times of 8 ms or less.

• Only one native resolution. Displaying resolutions either requires a video scaler, lowering perceptual quality, or display at 1:1 pixel mapping, in which images will be physically too large or won't fill the whole screen.

• Fixed bit depth, many cheaper LCDs are incapable of truecolor.

• Input lag

• Dead pixels may occur either during manufacturing or through use.

Plasma

   Pros:  

• Compact and light.

• High contrast ratios (10,000:1 or greater,) excellent color, wide gamut and low black level.

• High speed response.

• Near zero color, saturation, contrast or brightness distortion. Excellent viewing angle.

• No geometric distortion.

• Highly scalable, with less weight gain per increase in size (from less than 30 in (760 mm) wide to the world's largest at 150 in (3,800 mm)).

   Cons:

• Large pixel pitch, meaning either low resolution or a large screen.

• Noticeable flicker when viewed at close range

• High operating temperature and power consumption

• Only has one native resolution. Displaying other resolutions requires a video scaler, which degrades image quality at lower resolutions.

• Fixed bit depth

• Input lag

• Older PDPs are prone to burn-in

• Dead pixels are possible during manufacturing