In architecture, a deck is a flat surface capable of supporting weight, similar to a floor, but typically constructed outdoors, often elevated from the ground, and usually connected to a building. The term is a generalization of decks as found on ships.[from wikipedia]

In a building, a room is any space enclosed within four walls to which entry is possible only by a door that connects it either to a passageway, to another room, or to the outdoors, that is large enough for several persons to move about, and whose size, fixtures, furnishings, and sometimes placement within the building support the activity to be conducted in it.[from wikipedia]