Vertical support member. Columns can be made of almost any material, but are most commonly of wood, steel, polyurethane, fiberglass, aluminum, masonry, and others. Often they are made using a pedestal of wood or masonry, with a round, square, or tapered column on top. Columns can be purely decorative or have a structural purpose of holding up a roof or second story. When we use the term column, we are typically referring to a large stately support used on front porches. Porch Posts have a similar definition and purpose, but are typically a square post with a “turned” portion somewhere in the middle, while columns are commonly larger and either round, square, or tapered.