LEDs Defined:
Light-Emitting Diodes (LEDs) are solid-state semiconductor devices that convert electrical energy directly into visible light.

How it works:
The heart of an LED is composed of various semiconductor materials. When an electrical current passes through the diode, the recombination of positive and negative charges within the different compositions results in the emission of photons (light). The selection of different semiconductor materials will affect the frequency (color) of the emitted light.

It is low voltage:
LEDs are direct-current (DC) devices that require a transformer to convert alternating current (AC) to DC. The transformer also maintains a quality electrical supply for the LED device.

It is efficient:
Almost all of the energy in an LED radiates within the visible spectrum. By contrast, incandescent light sources have the lowest efficiency of all conventional sources because a major portion of its radiation (emitted energy) appears in the infra-red (IR) region of the spectrum. Other sources, such as fluorescent and HID lamps, are discharge sources, which have a higher efficiency but still have loss mechanisms in the electrodes and within the discharge itself. Fluorescent lamps have additional losses in the conversion of the UV radiation to visible radiation by the phosphor.

While white LEDs have already eclipsed Halogen efficacy, (20 lumens/watt), industry experts predict that LEDs will achieve 150-200 lumens per watt in the next decade.