Panel Doors
Panelled doors can add elegance to an entrance.
Panel doors consist of stiles (the vertical pieces) and rails (the horizontal pieces), with different-sized panels that fit between the stiles and rails. The rails and stiles are glued together, but the panels aren't; they're loose, so they can expand and contract with temperature and humidity changes. This is essential for exterior doors.
Flush Doors
Flush doors are practical. Flush doors, which are smooth, can be solid or hollow, but a solid-core door is safer and keeps the house quieter. Because flush doors are easier to make than panel doors, they can be mass produced. Panel doors are usually more decorative than flush doors.