As A1 Wheels / Rimco, Inc., we have a great knowledge base about truck wheels and because of this, find ourselves talking about wheels with people quite a bit. We find the greatest misconception we encounter is that rims and wheels are the same thing.
Rims are virtually the same as wheels, however, technically a rim is the part of the wheel that holds the tire. The wheel is the whole idea of the rim plus including structure to secure the rim to the vehicle. Hence, a tire is mounted on a wheel, then the tire/wheel assembly is bolted onto your truck or big rig.