Black, oolong, green, and white teas all come from the leaves of the Camellia sinensis plant.
Black tea, the most popular tea in North America, is often used to make iced tea. Black tea has been allowed to oxidize longer, growing stronger in flavor and possessing more caffeine. Some common type of black tea include Assam, Darjeeling, Ceylon, and Lapsang. Earl Grey, English breakfast, and Irish breakfast are blends of various black tea leaves with other flavorings.
Green tea, which is especially popular in Chinese and Japanese cuisines, is only allowed to oxidize for a short time. It's available in whole leaf or powdered (ground) forms.
The oxidation time for oolong tea is in between that of black and green tea.
White tea is made only from young leaves and buds of the tea plant, with minimal oxidation. Jasmine tea, a Chinese tea flavored with dried jasmine flowers, is usually made with green or white tea leaves.
Tea is referred to as “loose,” when it is not sold in tea bags.
Herbal teas or tisanes (including chamomile, ginseng, rooibos ("red tea"), hibiscus tea, yerba mate, and others) are infusions of dried herbs or flowers that are brewed in a manner similar to tea, but do not contain any actual tea leaves. Mint tea sometimes refers to a simple infusion of mint leaves, and sometimes to a combination of mint and green tea leaves.