Motor vehicles, full name powered vehicles, refer to vehicles equipped with power devices in the rail transit system, including two categories: locomotives and power cars. The motor vehicle is equipped with driving wheels, and the corresponding vehicle without a driving device is a trailer. For the train to run normally on the track, there must be a high-speed train to provide enough traction for the entire train, but it is not necessary to hang an unpowered trailer.
EMUs are railway vehicles equipped with wheel-driven machinery and equipment, not EMUs. Not only high-speed trains have high-speed trains, but all train types of transportation, including constant-speed EMUs, normal-speed trains, subway trains, light rail trains, monorail trains, and maglev trains, have high-speed trains.