Since Edison invented the light bulb, electric light has been constantly studied and new types of light sources have been developed. Among them, here are four types of light sources that are commonly used for home.
1. Incandescent lamps
This is the first light bulb invented by Edison. Incandescent lamps are simply made of tungsten filament, glass, and metal. When electric current flows through this tungsten filament, the filament emits light by converting heat energy into light energy (Thermal radiator).
2. Halogen lamps
Halogen is from same principle to incandescent lamp using heat energy for light. Halogen can make cooler color than incandescent. It is an incandescent lamp consisting of a tungsten filament sealed into a compact transparent envelope that is filled with a mixture of an inert gas and a small amount of a halogen such as iodine or bromine. (Wikipedia)
3. Fluorescent lamps
Fluorescent lamps or energy saving lamps are the next generation after the incandescent. A fluorescent lamp, or fluorescent tube, is a low-pressure mercury-vapor gas-discharge lamp that uses fluorescence to produce visible light. (Wikipedia)
4. LED lamps
LED is the newest bulb which is Light emitted Diode. A light-emitting diode (LED) is a semiconductor light source that emits light when current flows through it. Electrons in the semiconductor recombine with electron holes, releasing energy in the form of photons. This effect is called electroluminescence. (Wikipedia)