Lightbulb
From the Simple English Wikipedia, the free encyclopedia that anyone can change
A lightbulb (or light bulb, light globe, electric lamp, or just bulb) is a device that produces light from electricity when it is turned on. It is part of a bigger lighting device, such as a lamp. It usually stops working and has to be replaced more often than the rest of the device. In some places, lightbulb only means incandescent types, where the electricity passes through a wire called a filament, not fluorescent, where the electricity passes through gases. Fluorescent bulbs are more efficient -- they use less electricity compared to incandescent.
Most light bulbs fit into a socket, either by screwing or by a bayonet action, where they are pushed and twisted into the socket, and held in place by two small pins on the bulb. When they break, they must be replaced carefully. They get very hot when they are on, and take some time to cool off. There is danger of electric shock from touching the socket.
Electricity became available in the late 1800s. Light bulbs were invented earlier that century, but improvements by Thomas Edison made them practical for use at that time. Before that, people used candles and oil lamps for light. Electricity was more convenient. Some people still use oil and lamps, because they do not have electricity.