The document summarizes major architectural styles from the 20th century, including Modernism, Art Nouveau, De Stijl, Art Deco, the Bauhaus, Mid-Century Modern, and Post-Modernism. It provides examples of key works such as the Guggenheim Museum by Frank Lloyd Wright, the Barcelona Chair by Mies van der Rohe, and the Pompidou Center in Paris by Rogers and Piano. The styles reflected new technologies and materials as well as rejections or returns to historical references over the decades covered.