A door, usually glass-paned, used as for a rear or side entrance to a house. Usually refers to a sliding glass door with two sections moving on a track - one side slides open and the other remains stationary.
A mainly glass door that opens onto a patio, deck or backyard of a house. The door panel is comprised of stiles, rails and glass to allow for viewing. Originally homeowners asked for glass doors from a glazer, or someone who handles glass. This specialty product was created by distributors in small shops. In the 1960s when aluminum sliding doors became very popular, window manufacturers realized they could make patio doors to fill the openings that used to be filled by solid doors. At that point, the window companies started heavily promoting patio doors, made in aluminum, vinyl and wood. Door companies now also make them in wood, composites and steel.