Incandescent light bulbs are a type of electric light that produces light by heating a metal filament until it glows. Typically made of glass, these bulbs contain a tungsten filament that is heated to a high temperature when electricity passes through it. This process creates visible light, making them a common choice for household lighting. Although incandescent light bulbs are widely used, they are not the most energy-efficient option available. They convert only about 10% of the energy they consume into light, with the rest lost as heat. As a result, many people are switching to more energy-efficient alternatives like LED bulbs or compact fluorescent lamps (CFLs).