Doric

• Doric Temple of Isis in Delos, Greece.Medioimages/Photodisc/Photodisc/Getty Images
  
  The Doric order was named for the Dorians, a group of tribes that settled ancient Greece and Asia Minor around 1000 B.C. The style came into existence during the Greece's Archaic Period (700-500 B.C.). In the Doric order, the columns are fluted and stand directly on flat pavement (the stylobate) without a base. The capital (or top) of the column is composed of two parts: a flared slab called an echinus and a flat slab called an abacus. Atop the abacus rests a horizontal beam known as the entablature. An important aspect of Doric entablature is the frieze (wide central section), which is composed of alternating series of triglyphs (three bars) and metopes (stone slabs often decorated with relief sculpture).
  
  

Ionic

• Greek ruins with Ionic columns.Jupiterimages/Photos.com/Getty Images
  
  The Ionic order made its first appearance in the sixth century B.C. in Ionia, a coastal region in Asia Minor populated by Greek settlers. The Ionic style differs from the Doric in several respects. Ionic columns are thinner, rest on a base and have more vertical flutes than Doric columns. The capitals of Ionic columns have large scroll-like designs called volutes atop a smaller echinus often ornamented with egg-and-dart (a design pattern featuring oval objects alternating with arrows or dart-like objects). In the Ionic order, the frieze is usually carved with relief sculpture arranged in a continuous pattern around the building.
  
  

Corinthian

• Corinthian columns have ornate tops called capitals.Jupiterimages/liquidlibrary/Getty Images
  
  Named after the Greek city of Corinth, the Corinthian order was first developed in the Classical Period (500-336 B.C.) but was more commonly used in the Hellenistic (336-146 B.C.) and Roman periods (146 B.C. to A.D. 330). The most distinctive feature of the Corinthian order is the capital of the columns. Corinthian capitals have a bell-shaped echinus ornately decorated with plant leaves and spirals. Volutes occupy each corner, and unlike Doric or Ionian capitals, Corinthian capitals provide the same view from all four sides.
  
  

Examples

• The Temple of Hephaestus (also known as the Hephaisteion or the Theseion) is one of the best-preserved examples of ancient Greek architecture in the Doric style. Built between 450 and 440 B.C., the temple stands on the west end of the Agora of Athens. The Temple of Athena Nike at the Acropolis in Athens is a fine example of a classic Ionic-style structure. Constructed between 427 and 410 B.C., the temple is adorned with four Ionic columns in the front and rear. Near the Acropolis is the Choragic Monument of Lysicrates. Built by an arts patron in 335 B.C., it is one of the earliest examples of the Corinthian style.