Incandescent light bulbs consist of a glass enclosure which the bulb with an inert gas reduces evaporation of the filament and reduces the strength of the glass. Inside of the bulb is a filament of tungsten wire through which an electrical current passes. The current heats the filament to a very high temperature and than heated atoms vibrate. The electrons radiate excess energy in the form of black body radiation.

Those lamps usually also contain a glass mount on the inside. It supports the filament and allows the electrical contacts to run though the envelope without gas/air leeks. Many arrangements of electrical contact are used, such as a screw base, a bayonet base and for some lamps an electrical contact. Contacts in the lamp socket allow the electrical current to pass through the filament. To improve the efficiency of the lamp, the filament usually consists of coils of the fine wire.

One of the problems of the standard light bulbs is evaporation of the filament. The largest problem is that the variations in resistivity along the filament cause non-uniform heating.

During ordinary operation, the tungsten of the filament evaporates. Hotter and more efficient filaments evaporate faster. Because of this, the lifetime of a filament lamp is a trade-off between efficiency and longevity, The trade-off is typically set to provide a lifetime of several hundred hours for lamps used for general illumination. Other lamps, such as theatrical, photographic and motion-picture may have a useful life of only a few hours.