The "Classical Orders" refer to the architectural styles developed in ancient Greece and Rome. There are three main orders: Doric, Ionic, and Corinthian. Each order has distinct characteristics, including the design of columns and entablatures, which influence the overall aesthetic of buildings. The Doric order is the simplest, featuring sturdy columns without a base. The Ionic order is more slender and has scroll-like volutes on its capital. The Corinthian order is the most ornate, with elaborate leaf designs. These orders have significantly influenced Western architecture throughout history, seen in many modern buildings.