Electric power is carried by transmission lines to a substation and then distributed at a lower voltage to a transformer near a home. The transformer's output connects to the home's

The transformer's output connects to the home's Circuit Breaker panel. The two primary wires from the transformer enters the main circuit breaker. The main breaker lets you give power or cut power to the entire panel when necessary. Within this, all of the wires for the different outlets and lights in the house each have a separate circuit breaker or fuse.