What Is the Difference Between a Truck, a Tractor Semi-Trailer, and a Full Tractor-Trailer?

Those huge vehicles overwhelming the highways are called tractor semi-trailers because the back portion sits on wheels while the front end is supported by the tractor.

A full trailer rides on its own wheels with axles on the front and back and is connected to the tractor by a drawbar.

Sometimes a full trailer is attached to a semi, which is attached to the tractor.

A truck doesn’t have any attachments.

And that’s the difference between a truck, a tractor semi-trailer, and a full tractor-trailer.