Three-phase AC railway electrification

Three-phase AC railway electrification is a system for powering trains on railway tracks. In this system, three types of power (electricity) are used, called phases. Each phase of power is sent along a different rail, and the three rails are spaced a certain distance apart. The engine on the train has an electric motor that is able to use the three phases of power to generate motion, which drives the train.
The three phases are generated by a power station and they are sent to substations (electrical towers) along the tracks. The substations step down the voltage and distribute the three phases of power to the tracks. Then, when the train goes over those tracks, the electric motors on the engine are able to pick up the three power phases, producing motion and powering the train.