Difference between LED and LCD monitors

Difference between LED and LCD monitors
Traditional LCD monitors use CCFL (cold compact florescent light) to light the entire backside of the LCD panel. This is known as a "full array". The number of CCFL bulbs can vary from as few as 2 (inexpensive monitors) to as many as 7 (more expensive monitors). The more bulbs used, the better the uniformity of the backlight can be. Also uses more electricity.

In "LED monitors" LED lights are used to provide the backlight and they are more energy efficient than CCFLs. All consumer level "LED monitors" do not have a full array backlight. Instead they are edge lit which means the LED lights runs around the edge of the LCD panel. This allows for a thinner design and helps reduce power consumption. The draw back it that you are likely to see more "backlight bleeding" around the edges of the monitor and the center of the screen might not be as bright as the other parts of the screen.

Backlight bleeding is when more light shines through that is supposed to. The causes certain areas of the screen to be brighter than it should be. For example, black might look more like dark grey. All LCD monitors (CCFL and LED) suffers from some level of backlight bleeding, it is a limitation of the technology.

Lastly, the LED lights are not actually white. LED monitors use blue LED lights with a yellow phosphorous coating to imitate white. A few people have noted that colors appear slightly bluish on some LED monitors. That points to an inadequate coating on the blue LEDs. However, this is not a very common issue.

Source : jaguarskx From tom's Hardware "the authority on tech.