A tractor is a general large truck or semi-trailer that is towed by a tool between the front and the car. That is, the front of the car can be pulled out of the original car and pulled out of other cars. The car can also be pulled away from the original head by other fronts. The front of the car with the driving ability is called the tractor, and the car without the traction drive capability is called the trailer. The trailer is towed by the tractor. There are two ways to connect the tractor to the trailer: the first is that the front half of the trailer is placed on the traction saddle above the rear section of the tractor, and the bridge behind the tractor is subjected to a part of the weight of the trailer, which is half-hook; The front end of the trailer is connected to the rear end of the tractor. The tractor only provides the forward pulling force and drags the trailer to go, but does not bear the downward weight of the trailer. This is the full suspension.
It is often used for the transportation of large quantities of goods in the workshop or between workshops, such as the transportation of automobile manufacturing warehouses to assembly lines and baggage transportation at airports.