The three main types of columns used in Greek temples and other public buildings are Doric, Ionic, and Corinthian. The truest and most basic difference among the orders has to do with proportions (Doric columns, for example, being thicker and shorter, Ionic columns taller and slimmer). As a shortcut, the orders may be distinguished most easily by their capitals (the tops of the columns). As you can see from the following examples, the Doric capital has the simplest design; the Ionic has the curlicues called volutes, and the Corinthian has the acanthus leaves.

Doric Capital

Ionic Capital

Corinthian Capital

The Parthenon combines elements of the Doric and Ionic orders. Basically a Doric peripteral temple, it features a continuous sculpted frieze borrowed from the Ionic order, as well as four Ionic columns supporting the roof of the opisthodomos.