Incandescent Light Bulbs
They are source of artificial light that works by incandescence.
An electrical current passes through a filament, heating it and causing it to become excited.
The enclosing glass bulb prevents the oxygen in air from reaching the hot filament.
Otherwise it would be destroyed by oxidation.
Incandescent bulbs are also called electric lamps.
They can be produced for a wide range of voltages.
They have quite poor luminous efficiency so they are gradually being replaced by fluorescent lights, high-intensity discharge lamps, LEDs and other technologies.