There are three well-known columns in Greek architecture which include Doric, Ionic, and Corinthian. These columns were “borrowed” from the Romans by the Greeks and then changed into a style which became their own. The Doric column is recorded as the oldest at around 600 BC, followed by the Ionic in late 5th century BC, and then the Corinthian. There is a noticable difference among the columns as time progresses and each order becomes more decorative than the one preceeding it.



Resources
Classical Columns
http://www.bobvila.com
Doric Order
http://www.wikipedia.org
Ionic Order
http://www.wikipedia.org
Corinthian Order
http://www.wikipedia.org