In architecture, refers to detached vertical members, monolithic or built in courses, and made of stone, brick, wood, metal, or another solid material. They are characterized by being slender or narrow in proportion to their height, and of any shape in section. A pillar is typically used as a vertical support of some superstructure, as a stable point of attachment for something heavy and oscillatory, or standing alone as a conspicuous monument or ornament. The term may also be used for a natural pillar-shaped stone or other formation. The usage of "pillar" is broader than "columns," "posts," or "piers," which are basically pillars of particular shapes, proportions, and functions; a "pillar" may be, but is not necessarily, any of these three more specific members.