type of door made out of multiple sections that instead of swinging in or out, open up by folding into one side of a frame. Known for a vast opening they enable with simultaneous space saving they create. Bi-folding doors are often used as a garden, patio, or balcony doors but they can also be applied as interior doors tying together varied areas. They are compact, let a lot of light in, and enhance the general aesthetics of the room. Since they can fold away completely, they can open up and join separate spaces.