what is door

A door is a movable barrier that allows entry and exit from an enclosure, such as a building, room, or vehicle. Doors are generally made of a material suited to the doors task and are commonly attached by hinges, but can move by other means, such as slides or counterbalancing. The primary purpose of a door is to provide security by controlling access to the doorway (portal) . Doors are used to separate interior spaces for convenience, privacy, safety, and security reasons, and to secure passages into a building from the exterior for reasons of climate control and safety. Doors also have specialized uses, such as blast-proof doors, pet doors, trapdoors, and water doors.