In electronics and electrical engineering a fuse is a type of sacrificial overcurrent protection device. Its essential component is a metal wire or strip that melts when too much current flows, which interrupts the circuit in which it is connected. Short circuit, overload or device failure is often the reason for excessive current. A fuse interrupts excessive current (blows) so that further damage by overheating or fire is prevented.
Fuses have the advantages of often being less costly and simpler than a circuit breaker for similar ratings. However, the blown fuse must be replaced with a new device which is less convenient than simply resetting a breaker. In addition, replacing a fuse without isolating the circuit first can be dangerous in itself. As a result, residential circuit protection were superseded by low voltage circuit breakers.