Doors

Industrially they are manufactured in basic materials (wood, aluminum, glass, plastic). In the architectural space, they serve to separate rooms, facilitating both their isolation and access between them. They have various types of metal fittings of the hinge or "bibel" type and may have complementary locks, padlocks, bolts and slips, to close or open them more easily.

Doors can move in a number of ways (at angles away from the door/portal, sliding in a plane parallel to the frame, folding at angles in a parallel plane, or rotating along an axis in the center of the frame) to allow or prevent the entrance or exit. In most cases, the inside of a door coincides with its outside. But in other cases, the two sides are radically different.

Many doors incorporate locking or latch mechanisms to ensure that only a few people can open them (such as with a key). Doors may have devices such as knockers or bells by which people outside announce their presence. (In some countries, such as Brazil, it is customary to clap from the sidewalk to announce someone's presence.) In addition to providing access into and out of a space, doors may have the secondary functions of ensuring privacy by preventing unwanted attention from outsiders, separating areas with different functions, allowing light to enter and exit a space, controlling ventilation or airflow so that interiors can be more effectively heated or cooled, muffle noise, and block the spread of fire.