Electric company supply single-phase or 3-phase?
In most cases, the electrical company, supplies three-phase power voltage. A house is fed from one of these phases and the neutral, moreover, different houses in the same area are connected to different phases, but SHARE NEUTRAL.
The number of connected houses are arranged such that each phase has a load similar to the rest, that is, the load is balanced for the three-phase system.

There are other systems, such as two-phase (two phases and a neutral) but are of limited application in the world.