Filament bulbs, also known as incandescent bulbs, produce light by passing electricity through a thin wire filament, usually made of tungsten. This process heats the filament until it glows, emitting light. They are commonly used in homes and businesses due to their warm light quality and simple design. However, filament bulbs are less energy-efficient compared to other lighting options like LED bulbs or CFLs. They convert a significant amount of energy into heat rather than light, leading to higher electricity costs. Despite this, many people still prefer them for their aesthetic appeal and the quality of light they provide.