In architecture or other construction, refers to stiff, vertical, relatively isolated members of considerable length. Posts are typically round, square, or rectangular in cross-section and are used in building as supports for a superstructure or to provide a firm point of lateral attachment. They are characteristically relatively undecorated and made of a single timber, but may be made of stone, metal, another material, or composite materials. The term is particularly used for any main vertical support in a timber frame structure. For square uprights in classical style, and for square and rectangular masonry uprights, use "piers (supporting elements)"; for most cylindrical uprights, and for all uprights in steel and concrete frames, use "columns (architectural elements)."