A circuit breaker is an electrical device designed to protect an electrical circuit from damage caused by overloads or short circuits. It automatically interrupts the flow of electricity when it detects a fault, preventing potential hazards like fires or equipment damage. Circuit breakers can be reset after they trip, making them a safer alternative to fuses, which must be replaced. These devices come in various types, including miniature circuit breakers (MCBs) and residual current circuit breakers (RCCBs), each serving specific functions. They are commonly used in residential, commercial, and industrial settings to ensure electrical safety and reliability.