GFCI (Ground Fault Circuit Interrupter) is an electronic device to protect people from serious injury due to electric shock.

The advantage of using GFCI is that, even amounts too small to activate a fuse or circuit breaker, they can detect even small variations in the amount of current flowing through an electrical product. 

GFCI work quickly enough to help protect consumers from severe electric shocks and electrocution while most common circuit breakers (thermal snap action) take far too long to open the circuit. 

ALCI is an abbreviation for Appliance Leakage Current Interrupter. It is a safety plug built-in ground fault interrupters on the end of power plugs. ALCI plugs are designed to prevent electrical shocks.