An LED light has many advantages over the old fashioned light bulb:
A BIG plus is that LED lighting is environmentally friendly, as they don’t contain mercury.
They use very little electricity compared to incandescent lights, typical power usage ranges from 1 watt to about 8 watts.
An LED light last more than 5 years of continuous use before losing their light intensity,
LEDs are solid state electronic components, they are actually a type of diode, so they can withstand a lot of harsh treatment without breaking. When you switch an LED light on it will produce full light instantly, useful in applications where instant light is needed for emergency lighting. When used to replace standard incandescent bulbs they can be used in dimming circuits and they don’t turn yellowish when dim.
They don’t have electronic ballasts like CFLs so will not cause radio and TV interference as Fluorescents sometimes do.
LED lights are useful for outdoor night lights because they don’t emit UV light, which attracts insects as other lights do.

One disadvantage of an LED light is it only radiates light in a single direction, like a spotlight, so  they are great for torches but when used in the home cannot replace room lights, although advances are being made in multi-bulb units that use many small lights shining in different directions to give a spread of light, and other methods use a diffusing bulb covering much like the frosted glass you see on a light bulb.