Typically one door panel is stationary and the other opens by sliding horizontally on tracks. Sliding Patio Doors may include more than two panels. Single, double, or French Swinging Patio Doors are available in many styles and glass types to provide clear viewing or obscured for more privacy. Open up an entire room to the great outdoors with a Folding Patio Door System. These doors open accordion style and can be designed with multiple panels.