Panel doors, also called stile and rail doors, are built with a frame and panel construction.
Stiles are vertical boards that run the full height of a door and compose its right and left edges. The hinges are mounted to the fixed side the "hanging stile", and the handle, lock, bolt, and/or latch are mounted on the swinging side the "latch stile".
Rails are horizontal boards at the top, bottom, and optionally in the middle of a door that join the two stiles and split the door into two or more rows of panels.
Mullions are smaller optional vertical boards that run between two rails, and split the door into two or more columns of panels.
Muntins are optional vertical members that divide the door into smaller panels.
Panels are large, wider boards used to fill the space between the stiles, rails, and mullions. The panels typically fit into grooves in the other pieces, and help to keep the door rigid. Panels may be flat, or in raised panel designs.
Lights or pieces of glass are used in place of a panel, essentially giving the door a window.