The answer to 'what is a circuit breaker' is a safety device that automatically cuts off the flow of electricity in an electrical circuit when it detects a problem, such as an overload or short circuit. Circuit breakers are essential for protecting your home's electrical system and preventing fires or damage to your appliances and electronics.
When too much electricity flows through a circuit, the circuit breaker will 'trip' and open the circuit, interrupting the power supply. This prevents the wires from overheating and potentially starting a fire. Circuit breakers can be reset by simply flipping the switch back to the 'on' position once the problem has been identified and resolved.