Three-phase is a method of electrical power generation, transmission, and distribution that uses three alternating currents, each set 120 degrees apart in phase. This system is more efficient than single-phase power because it provides a constant power supply, reducing fluctuations and improving the performance of electrical devices. In a three-phase system, the three currents can be transmitted over fewer wires, which saves material and reduces costs. It is commonly used in industrial applications and large motors, as it allows for smoother operation and higher power output compared to single-phase systems.