A sliding door mechanism is a device or system that is used to open and close a sliding door. It usually consists of a pair of metal rails or guides that are attached to the top and bottom of the door, and a pair of wheels or bearings that are attached to the sides of the door. When the door is opened, the wheels or bearings glide over the rails and slide the door open or closed. Sliding door mechanisms are often made of steel or aluminum and are designed to be strong and durable. They are frequently used on sliding doors in houses, apartments, offices, and other buildings to save space and to make the door easy to open and close.