Roof Racks are set of bars secured to the roof of a motor car. It is used to carry bulky items such as luggage, bicycles, canoes, kayaks, skis, or various carriers and containers.
The three most common components of a roof rack system are (side) rails (or tracks), towers which clamp or otherwise attach to the rails, and mounts, which secure the bulky items to the rack system.
Some automobiles have fittings for proprietary racks which mate with reinforced lugs in the roof. Other vehicles have a factory-installed permanent roof racks.