A rail is a thin and elongated piece of wood, such as a board or beam. In cabinetry, the top and bottom horizontal pieces that form the frame of a cabinet are known as rails.

The rails are a crucial component of cabinet frames and are joined with vertical pieces of wood, known as stiles, to form a frame and panel construction. Typically, a cabinet door or frame will have two rails, one at the top and one at the bottom, and one stile on each side. This method of construction is commonly used in the manufacturing of cabinetry and is known as the frame and panel technique. A door created using rails, stiles, and a panel is often referred to as a “five-piece door”.

Rails can be made of either solid wood or manufactured wood products and are sanded and stained or coated with a veneer that matches the overall appearance of the cabinet. This design approach is utilized in many cabinet styles to provide both visual appeal and structural support to the cabinet unit.