Light Emitting Diode
A light-emitting diode (LED) is a semiconductor device that emits light when an electric current is passed through it. Light is produced when the particles that carry the current (known as electrons and holes) combine together within the semiconductor material.
Since light is generated within the solid semiconductor material, they are described as solid-state devices. The term solid-state lighting, which also encompasses organic LED's (OLEDs), distinguishes this lighting technology from other sources that use heated filaments (incandescent and tungsten halogen lamps) or gas discharge (fluorescent lamps).
NOTE :- The bigger one wire of led is +ve and other is -ve .
RGB LED's consist of one red, one green, and one blue LED. By independently adjusting each of the three, RGB LED's are capable of producing a wide color gamut. Unlike dedicated-color LED's, however, these obviously do not produce pure wavelengths. Moreover, such modules as commercially available are often not optimized for smooth color mixing.
Types of LED