Sliding patio doors, as their name implies, are known for having panels that slide along rails positioned on the top and bottom edge of the door frame. Some sliding doors feature two sliding panels while others only have one sliding panel and one fixed panel. The panels take up just as much space as the door frame, making them great for areas with limited floor space. Furthermore, because the panels are fully supported by the door frame, a sliding door can afford to have larger glass panels than French doors, which may require stiles for extra support.