Tea is an aromatic beverage commonly prepared by pouring hot or boiling water over cured or fresh leaves of the Camellia sinensis, an evergreen shrub native to East Asia. After water, it is the most widely consumed drink in the world. There are many different types of tea; some, like Darjeeling and Chinese greens, have a cooling, slightly bitter, and astringent flavour, while others have vastly different profiles that include sweet, nutty, floral, or grassy notes. Tea has a stimulating effect in humans primarily by its caffeine content.