Parts of a Lamp

For our purposes, the lamp has 3 basic parts: the Cap or Base, the Bulb and the Filament, illustrated in the above image. These characteristics serve to distinguish one lamp from another and serve the following purposes:

  1. Cap/Base - The Cap transfers electrical energy from the source (e.g. transformer, power supply or line voltage source) and sends it to the filament.
  2. Bulb - The Bulb is usually a glass envelope that protects the filament from mechanical damage and provides a proper operating environment. The Bulb is usually filled with a gas during the manufacturing process to prolong the time the filament will produce light without burning out. 
  3. Filament - The Filament is a thin wire made of tungsten or another metal that receives the electrical energy from the source and converts it into light.

* Note: In LED Technology, the filament is replaced with one or more Light Emitting Diodes (LEDs) configured in an way to produce a certain amount of lumens over a specific pattern. In fluorescent and compact fluorescent the electrode coil serves the same function as the filament.