What are the benefits of LED Monitors while comparing with LCD Monitors?...

First of all, LCD and LED technologies are the same thing. They BOTH use liquid crystal display technology to display the image. The difference is in the type of backlight they use. Monitors which are called LCD mostly use fluorescent tubes (Cold Cathode Fluorescent) as the backlight whereas monitors called LED use light emitting diodes as the backlight. There are two main types of LED backlight. WLED uses 'white' LEDs at the edge of the screen, whereas RGB LEDs are distributed all over the screen and can emit red, green or blue light as required. Some of the main things you need to look for in a monitor are: 1) Evenness of backlight (is the backlight illumination even over the whole screen) 2) Contrast ratio (how black is 'black'?) 3) Colour accuracy (how natural is the colour reproduction? do flesh tones look natural? is there a good range of greens? reds are neither muddy nor over-saturated.) 4) Angle of view (how far to each side of the screen can you be before the picture loses quality?) 5) Refresh speed or 'image latency' (does the screen show moving images clearly or do quickly moving objects blur at the edges and become fuzzy) 6) Reflectivity (does the screen reflect bright objects in the room or has it a matt surface and anti-reflective coating?) There is MUCH more to buying a TV or monitor than this, of course, and the best way to choose is to start with your budget - How much can you afford? Then know what you want to use if for (mainly Internet and web pages, watching videos/TV, viewing and editing photos &c) because that will have a bearing on what limitations you are prepared to accept. There are very many guides to be found on the Internet. This one is quite good and seems not too technical:

As Owlwings said the screen is the same, it is the backlight which is different. LED are providing a better contrast and have a longer life than fluorescent tubes, but they have a flickering effect noticeable when the brightness is low that can damage the eyes (At 60 Hz a LED is on and off 60 times/second when a fluorescent tube is always on).