A Light Emitting Diode (LED) is a semiconducting gadget that converts electricity into visible light. A form of Solid State Lighting (SSL), LEDs is designed to be more efficient, durable, last longer and adaptable. The light produced is usually monochromatic, existing at a particular wavelength.

The LED is essentially made up of processed material with N-type semiconductors (with extra negatively charged particles), and P-type semiconductors (comprising of extra holes and more positively charged particles). A P-N junction is formed when these semiconductors combine. Upon the application of an onward charge, negatively charged particles (electrons) move towards the P area and holes move towards the N area. Light is formed when electrons and holes combined at the junction.

While similar to many diodes, LEDs have distinguishing differences such as clear casing that allows infrared energy to pass. The semiconductor material also serves to contain electric current through energy bands. How these bands are separated, determines the photon energy (light) produced and in turn, the colors.

LEDs are usually used for indicator lights (bar-graphs, readouts, etc.), LCD panel backlighting, data transfer via Fiber optics (their capacity for modulation enables greater bandwidth) and remote controls.