A light switch is a simple electrical device used to control the flow of electricity to a light fixture. When the switch is turned on, it completes the circuit, allowing electricity to flow and the light to illuminate. When turned off, the circuit is broken, and the light goes out. Light switches come in various types, including toggle switches, rocker switches, and dimmer switches. They are typically mounted on walls and can be operated manually. Some modern switches are also designed to be controlled remotely or through smart home systems, allowing users to manage lighting from their smartphones or voice assistants.