The Capital is a circle topped by a square. There are 20 sides on the shaft of a Doric Column. The Doric column is the simplest version and also had no base.
Ionic shafts are taller than the Doric ones; this makes them look more slender. The shafts also had a characteristic called entasis, enabling the columns to look the same width all the way up to the top instead of appearing to get smaller. The bases looked like stacked rings and the capital had scrolls above the shafts for style.
Corinthian Columns are the most decorative. They also use entasis to make the shafts appear to be straight. The capitals have flowers and leaves underneath a small scroll. Also the roofs on top of Corinthian Columns are flat, unlike those of the Ionian and Doric styles.