On-off switches, also known as toggles, are devices used to control the flow of electricity in a circuit. They are typically used to turn electrical devices on and off, and are composed of two positions: on and off. When the switch is in the on position, the circuit is closed and electricity can flow through it; when the switch is in the off position, the circuit is open and no electricity can flow. On-off switches are commonly found in household appliances, such as televisions, computers, and lamps.