A bus (archaically also omnibus, multibus, or autobus) is a road vehicle designed to carry passengers. Buses vary in capacity from 8[not in citation given] to 300 passengers. Buses are widely used public transportation.

The most common type of bus is the single-decker bus, with larger loads carried by double-decker buses and articulated buses, and smaller loads carried by midibuses and minibuses. A luxury, long distance bus is called a coach. A bus is powered by a combustion engine, although early buses were horse drawn and there were experiments with steam propulsion. Trolleybuses use overhead power lines. In parallel with the car industry bus manufacturing is increasingly globalised, with the same design appearing around the world.