What are the three main tea eras? How are these eras significant?

There are three main eras of tea: the Boiled Tea, the Whipped Tea, and the Steeped Tea. Okakura again emphasizes that tea, though seemingly a tiny part of one's life, can speak volumes about a culture. As with vintage and concern with years with wine in Europe, different tea periods can tell us about the different eras of Japan.