A door is a hinged or otherwise movable barrier that allows ingress (entry) into and egress (exit) from an enclosure. The created opening in the wall is a doorway or portal. A door's essential and primary purpose is to provide security by controlling access to the doorway (portal). Conventionally, it is a panel that fits into the doorway of a building, room, or vehicle. Doors are generally made of a material suited to the door's task. They are commonly attached by hinges, but can move by other means, such as slides or counterbalancing.
Stone door in Hampi (India)
A massive door socket from Persepolis (modern-day Iran)
Roman folding doors at Pompeii, from the first century AD, similar with Neoclassical doors from the 19th century
Roman wall painting of an ornate door, in the Villa Boscoreale (Italy), from the first century AD
In a building or ship, a room is any enclosed space within a number of walls to which entry is possible only via a door or other dividing structure. The entrance connects it to either a passageway, another room, or the outdoors. The space is typically large enough for several people to move about. The size, fixtures, furnishings, and sometimes placement of the room within the building or ship support the activity to be conducted in it.
Neolithic room at Skara Brae, Orkney, c. 3,000 BC
Castle Howard, "Lady Georgianas' Dressing Room"
Image: Ateneul Român Sala
Image: Salle des catalogues de la Bibliotheque Mazarine Paris