Answer: LED is an abbreviation for a light-emitting diode. An LED is an electronic light source. A diode is not a light bulb. Traditional incandescent light bulbs heat tungsten filaments until they glow, like a toaster heating element. These filaments gradually evaporate until they break and burn out. LEDs work on a totally different premise, similar to transistors or other electronics along those lines. There is no filament to burn out. They're also a much more efficient light source, producing considerably more light per watt than a traditional bulb. Most LEDs are about 2/10 of an inch in diameter and about 1/ 3 of an inch in length. Whereas typical household lamps require 110/220 volts, an LED uses just two or three volts. What's more, typical household lamps are rated for 1,500 to 2,000 hours while LEDs can last 50,000 hours or more.
LED lighting has been around for many years and is just now really coming into its own. For years, the Light Emitting Diode was simply used as an indicator or display light in various small-scale applications. Think of those old Texas Instruments calculators, or your blinking VCR light. LED is a solid-state technology. This means there is no glass bulb, no pressurized gases, no mercury and no burning filament. In the traditional bulb, Heat was the main result while light stood as a mere by-product of electrifying the filament. With LED technology, what you have is a circuit board and a computer chip. The properties of the chip create light that is generated and focused through a plastic diode to create light. Depending on the chip and materials used, different colors in the color spectrum can be created. Early on the easiest color to create was red, which is why your calculator and VCR had red display lights rather than any other color. For many years, there were no advancements in LED technology and very little change in lighting technology over all; changes that did occur were mostly just plays on a theme. Metal halide, fluorescent, etc. were all just different ways to do the same thing with different effects. In recent years, LED technology has completely changed and reinvented the light bulb and the way we think about lighting in general. This was not really possible prior to the technological revolution of the ‘90s and the rapid advancement of the microchip. The same advancements that spurred the computer to reach dizzying levels of efficiency have also done the same for the LED. Just as computers have become faster and cheaper, LED lights have become brighter, smaller, less expensive, and more sophisticated.
Light emitting diodes, commonly called LEDs, are real unsung heroes in the electronics world. They do dozens of different jobs and are found in all kinds of devices. Among other things, they form the numbers on digital clocks, transmit information from remote controls, light up watches and tell you when your appliances are turned on. Collected together, they can form images on a jumbo television screen or illuminate a traffic light. Basically, LEDs are just tiny light bulbs that fit easily into an electrical circuit. But unlike ordinary incandescent bulbs, they don't have a filament that will burn out, and they don't get especially hot. They are illuminated solely by the movement of electrons in a semiconductor material, and they last just as long as a standard transistor.
LEDs are commonly used in aesthetic, effect, or specialty lighting applications, including architectural highlighting. Most traffic lights and exit signs, for example, now use red, green or blue LEDs.