A patio door is a large door that provides access from the inside of a home to an outdoor patio or deck. These doors are typically made of glass, allowing natural light to enter the space while offering a view of the outside. They can slide open or swing open, depending on the design, and are often used to enhance the connection between indoor and outdoor living areas. Common types of patio doors include sliding doors and French doors. Sliding doors consist of two or more panels that glide on a track, while French doors usually feature two hinged doors that open outward. Both styles can improve ventilation and accessibility, making them popular choices for homeowners.