Circuit breakers or fuses are some of the most important safety devices in your home, preventing overloaded circuits that could overheat and cause a fire. Circuit breakers, usually found in breaker panels, are the most common form of overload protection found in homes. Fuse boxes are usually found in older homes built before circuit breaker technology was commonplace. Circuit breakers and fuses are similar in function, though different in design.
Fuses use a filament that melts when overloaded to disconnect the circuit. A fuse must be thrown out and replaced completely when blown, and cannot contain GFCIs like a circuit breaker. It is possible to accidentally use an over-sized fuse; a 30 amp fuse can fit in a 20 amp circuit, which is a dangerous fire hazard.