architectural orders :

(An architectural classification system based on the shape and proportion of classical design elements found in Greek and Roman structures). Orders fall into five styles that are exemplified by their columns: Doric (smooth, simple, round) developed on the Greek mainland, Southern Italy, and Sicily by the 7th century, BCE; Ionic (scrolled-shaped decoration with fluted columns) developed in Ionia (modern Turkey) by the 6th century, BCE; Corinthian (elaborate capital detail with acanthus leaf decoration) was developed late 5th century and used primarily by the Romans; Tuscan (Roman adaptation of Ionic but with smooth columns with simplified capitols); and, Composite (a late Roman development using a highbred of Corinthian and Ionic).