A plane has several busses on it. Each of those has different purposes in relating the operation of the aircraft.
Thus you'd expect something like this:
A couple main busses,which take power straight from the generators. The most critical thing these busses feed is the the essential bus,which ensures that power is provided to the essential items at all times, as they are required to maintain safe flight.
Also going off the main busses, are utility busses, which power everything else required to operate the aircraft, and finally, a service bus, which would power things like the galley and passenger items.
Should a generator drop offline, there will still be power to the essential bus, as the main bus (if automatic, or the pilots, if manual) will shed the other busses in order of least importance that it has to in order to feed the essential bus.
Two all beef patties, special sauce, lettuce, cheese, pickles, onions on a sesame seed bun.