Final answer:
The horizontal cross pieces on a raised panel wood door are known as rails, which are not to be confused with stiles, mullions, or louvers.
Step-by-step explanation:
The horizontal cross pieces on a raised panel wood door are known as rails. These are distinct from the stiles which are the vertical pieces that frame the door's sides, and the mullions, which are vertical bars between the panes of glass in a window. In contrast, louvers are angled slats or flat strips fixed or suspended.
At regular intervals in doors or windows to allow air or light to pass through. An understanding of these components is essential when studying architectural elements or even doing woodwork that involves constructing or repairing doors. Raised panel wood doors have horizontal cross pieces called rails.