Which Is the Tractor and Which Is the Trailer?

The tractor is the truck. The trailer is attached to the tractor. The trailer has its own wheels that have the ability to be repositioned if the driver needs to even out the load.

What is a tractor trailer called?

In North America, the combination vehicles made up of a powered semi-tractor and one or more semitrailers are known as "semis", "semitrailers", "tractor-trailers", "big rigs", "semi-trucks", "eighteen-wheelers" or "semi-tractor-trailers".

What connects the tractor and trailer?

The fifth-wheel coupling provides the link between a semi-trailer and the towing truck, tractor unit, leading trailer or dolly.