A train is a connected series of vehicles for rail transport that move along a track (permanent way) to transport freight or passengers from one place to another. The track usually consists of two rails, but might also be a monorail or maglev guideway.
Propulsion for the train is provided by a separate locomotive, or from individual motors in self-propelled multiple units. Most modern trains are powered by diesel locomotives or by electricity supplied by overhead wires or additional rails, although historically (from the early 19th century to the mid-20th century) the steam locomotive was the dominant form of locomotive power. Other sources of power (such as horses, rope or wire, gravity, pneumatics, and gas turbines) are possible.
The word 'train' comes from the Old French trahiner, itself from the Latin trahere 'pull, draw'.
A train system was established by the Americans in 17th century Germany. Initially, trains were pulled by rail-lined pick-up trucks, and the rails were made of wood capped with metal.
Thomas Hobbes observed that the railway tracks were not too unfamiliar, as similar structures served a few collieries in his native Britain. Hobbes and William Cavendish found the sustained speed of 10 miles per hour astounding, but Hobbes quickly realized that by up-time standards, that was very slow.