The total weight of a trailer carried by itself is called a full trailer, which is usually referred to as a trailer for short. Features: itself no power, independent bearing, relying on other vehicles traction of the vehicle trailer is its design and technical characteristics need to be towed by the car, in order to normal use of a power-free road vehicles, used for carrying people and/or goods; special purpose
Full-trailer or semi-trailer does not have its own power device, they and the traction of the automobile train composed of the automobile belongs to the automobile category. A semitrailer is a trailer with an axle behind the center of gravity of the vehicle (when the vehicle is loaded evenly) and with a coupling that transfers horizontal or vertical forces to the tractor.
That is, the total weight of the trailer is partly borne by the tractor. Its characteristics: no power of its own, with the main vehicle common load, rely on the main vehicle traction vehicles