A column is a vertical architectural work that can either stand alone or be an important part of the overall design structure. It is often used as both decoration and support in the post and lintel system of architecture. The column has many variations but is often defined by its capital. The capitals from the three Classical architectural orders are Doric, Ionic, and Corinthian. Columns are often constructed of drums that are placed on top of one another. Flutes are sometimes used to give the illusion of its being made from one piece of stone. A purely decorative use of this idea is the pilaster.