Plugs and sockets are used to removably connect electrically operated devices to a power supply. A plug has protruding pins that fit into matching slots in a wall-mounted socket or power point. The main advantages of plugs and sockets are that they allow devices to be easily connected and disconnected from a power source using a switch and act as a circuit breaker to keep appliances safe. Common applications include providing emergency, uninterruptible, or isolated power sources for critical equipment.