Single-phase power is a two-wire alternating current (AC) power circuit with one power wire and one neutral wire. Three-phase power is a three-wire AC power circuit.
A three-phase power supply delivers power at a more consistent rate as there are fewer peaks and dips in voltage, than with a single-phase power supply. Residential homes are usually served by a single-phase power supply, while commercial and industrial facilities usually use a three-phase supply.
