GFCI or GFI stands for Ground Fault Circuit Interrupter. The receptacle has a built in circuit that will detect leakage current to ground on the load side of the device and interrupt power, preventing a hazardous ground fault connection. GFCI receptacles are required by National Electric Code NFPA-70 in a variety of indoor and outdoor locations, usually when near water such as in the kitchen or bathrooom.
