A residual current circuit breaker (RCCB) is a safety device used in electrical systems to prevent electric shocks and electrical fires. It works by detecting imbalances in the electrical current flowing through a circuit. If it senses that some current is leaking, which could indicate a fault or a person coming into contact with electricity, it quickly disconnects the power supply. RCCBs are essential in homes and commercial buildings, providing an extra layer of protection beyond standard circuit breakers. They are often used in conjunction with fuses and circuit breakers to ensure comprehensive electrical safety.