A cornice is an ornamental molding that runs along the top of the walls in a room, serving as a decorative feature that conceals the joint between the walls and ceiling. Originating from classical architecture, cornices can be simple or elaborately decorated, and they come in various designs and materials such as plaster, wood, or polystyrene. In addition to their aesthetic function, cornices can also help to hide cracks and imperfections where walls meet ceilings and can be used to enhance the architectural style and character of a space.