A light bulb is a type of lamp that uses a resistor to heat a thin wire (usually tungsten wire in modern times) to incandescence through electricity, in order to emit light. The periphery of the electric bulb is made of glass, which keeps the filament under a vacuum or low-pressure inert gas to prevent oxidation of the filament at high temperatures.

And light is a form of energy that is released by atoms. It is composed of many small clusters resembling particles, which have energy and momentum but no mass. These particles are called visible photons and are the most fundamental units of light. When electrons are excited, atoms will release visible photons. If you already know how atoms work, then you know that electrons are negatively charged particles walking around the nucleus.