Difference between LCD and LED

LCD stands for "liquid crystal display". LED stand for "Light Emitting Diodes” also work on the base of liquid crystal displays.  While both LCD and LED  TVs base on liquid crystals system, it’s the backlighting that really makes them different from one another. All the LED TVs are basically LCD but all the LCD TVs are not LED,s simple just as all the eagles are birds but all the birds are not eagles.

Liquid crystal display explained

Liquid crystals to help create an image in both the LCD and LED TVs, The difference in these both are the backlights.  While a standard LCD uses fluorescent backlights, an LED uses light-emitting diodes for backlights.  LED monitors usually have superior picture quality, but they come in varying backlight configurations.  And some backlight configurations create better images than others which is generally known as different resolutions.

LCD vs LED a brief history

Plasma display were most common display before liquid crystal display until 2014. Than this system replaced by liquid crystal system in LCD TVs and LED TVs.

Liquid crystal 

There are three state of matters liquid solid and gases , out of these there are some strange blend of different states .

A liquid crystal is a substance that has properties of both a solid and a liquid.  When you get to the upper tiers of science, you begin to discover that everything you once knew is wrong.

The arrangements of molecules in liquid crystal is Typically, bunch up dense and unstructured.  But when the liquid crystal is exposed to electricity, the molecules suddenly expand and arrange themselves into a very structured, interconnected shape.

Pixel

Pixels are the basic building blocks of a digital image.  A pixel is a small dot that can emit colored light.  Your display is composed of thousands of pixels, and they're in a variety of different colors to give computer interface and the webpage that you're currently reading and video or image which your seaing like on LCD and LED TVs screens.

Every pixel is composed of three basic color filters, which are called "subpixels."  There's RGB-colured known as red, blue, and green subpixel for every pixel.

How display work in LED and LCD TVs

Every pixel is composed of two glass sheets, and the outermost sheet has the subpixels. The liquid crystals are sandwiched between the two sheets.

Backlight behind the screen produced white light liquid crystal is in there liquid arrangement known as randomly arrange light can't pass through it but while pixel is used when electricity applied they arrange themselves in orderly arrangement straighten out to allow light pass through it.

Main difference is type of backlighting 

Standard LCD monitors employ “cold cathode fluorescent lamps,” also known as CCFLs as backlights. These fluorescent lights are evenly placed behind the screen so that they deliver consistent lighting across the display. All regions of the picture will have similar brightness levels. Commonly Known as backlighting full-array.

LED TVs used  light-emitting diodes,”instead of fluorescent lamp. which are extremely small lights. There are two methods of LED backlighting: full-array backlighting and edge lighting.

With full-array backlighting, the LEDs are placed evenly across the entire screen, similar to an LCD setup. But what’s different is that the LEDs are arranged in zones. Each zone of LED lights can be dimmed (also known as local dimming).

Local dimming is a very important feature that can dramatically improve picture quality. The best images are ones that have a high contrast ratio; in other words, images that have both very bright pixels and very dark pixels simultaneously.

When there’s an area of the picture that needs to be darker (a night sky, for instance), the LEDs in that region of the picture can be dimmed to create a truer black.

There are no local dimming capabilities in LCD,s and edge-lighted displays in LED,s.

So evenly distributed backlighting with local dimming, enhance the picture qualities in LED,s.

These are the basic difference of LCD and LED.