LEDs are light emitting diodes. These are electronic components that convert electrical energy directly to light through the movement of electrons within the material of the diode. LEDs are important because due to their efficiency and low energy, they are beginning to replace most conventional light sources.
LEDs have no gases, filaments and no moving parts to fatigue. They provide light through a one-step process that takes place within the diode. There is no glass to break or screwed contacts to loosen.
The term solid state lighting is used because the electronics produce light directly from solid materials in which the electrons are embedded. This is unlike other technologies, for example fluorescent technology, which requires a gaseous discharge medium to initiate production of light.