Herbal teas — less commonly called herb teas or tisanes — and fruit teas are beverages made from the infusion or decoction of herbs, spices, fruits, or other plant material in hot water. They do not usually contain caffeine.
Black tea contains caffeine. ... Black tea is also full of healthy substances called polyphenols. Polyphenols are antioxidants that can help protect your cells from DNA damage. Some scientists think that specific antioxidants in tea, including polyphenols and catechins, may help prevent some types of cancer.
Green tea is a type of tea that is made from Camellia sinensis leaves that have not undergone the same withering and oxidation process used to make oolong and black tea.