An electrical fuse is a circuit-interrupting safety device designed to protect an electrical system from damage caused by excessive current. Its operation relies on a precisely calibrated element, typically made of a metal alloy, designed to withstand normal operating currents while melting rapidly when the current exceeds a predetermined threshold. This melting action creates an open circuit, effectively stopping the flow of electricity before components or wiring can overheat, potentially causing fire or catastrophic equipment failure. The selection of a fuse depends on the maximum allowable current and the voltage of the circuit, ensuring that the failure point is reliable, predictable, and safely isolates the affected segment of the system.