Circuit breakers are safety devices used in electrical systems to prevent overloads and short circuits. They automatically interrupt the flow of electricity when they detect a fault, protecting both the wiring and connected devices from damage. This helps to prevent fires and other hazards that can occur due to excessive current. When a circuit breaker trips, it can be reset manually once the issue is resolved. There are different types of circuit breakers, including miniature circuit breakers (MCBs) and residual current devices (RCDs), each designed for specific applications and levels of protection.