Live rails, also known as energized rails or third rails, are an essential component of electric rail systems. Typically, they supply electrical power to trains through direct contact with the trains' power collection devices. However, there are a few synonyms for live rails, including third rail, conductor rail, return rail, and running rail. The term "third rail" refers to the additional rail that runs along the side of the track as an electric power supply. The conductor rail is a steel rail that acts as an electrical conductor for the train's traction system. The return rail is another synonym that refers to the rail that completes the electrical circuit. Finally, the running rail is synonym for the standard railway track rail that supports the train's weight.