What is molding in a house called?

Molding in a house is broadly referred to as architectural millwork, trim, or decorative molding, encompassing a wide variety of specialized profiles installed at different junction points throughout a room. Depending on its exact location and functional purpose, specific types of molding are given unique names such as crown molding where walls meet the ceiling, baseboards along the floor, chair rails at mid-wall height, and casing surrounding doors and windows. Other specialized styles include picture rails for hanging artwork without damaging drywall, wainscoting components for decorative wall paneling, and quarter round for covering small flooring expansion gaps. Each of these distinct profiles serves to hide structural joints, cover rough construction gaps, protect walls from damage, and add an overarching sense of elegance and finished architectural character to residential and commercial interiors.