Common teas made from Camellia Sinensis:
Green tea - Green tea is heat-cured using a variety of methods, temperatures and durations to produce different flavor variations. Its composition is denser and more durable than white tea, and its flavor fuller, ranging from sweet to smoky. Green tea, as well as white, are generally made from the youngest leaves.
White tea - the purest form of the Camellia Sinensis leaf, white tea is simply picked, washed and dried, giving it a fragile, flaky texture when dry and a very light gentle flavor. White tea is the least processed of all the teas, and therefore is highest in antioxidant, while it is lowest in caffeine.
Oolong tea - Oolong is usually made from the darker, richer leaves, and is partially fermented before curing, giving it a much richer, more complex flavor and velvety texture. Good oolong is often considered the "champagne" of tea; unfortunately, most Americans never get to taste good oolong, for reasons noted below.
Black tea - Black tea also comes from the same plant, but is fermented, giving it a much darker color and stronger flavor. Black tea is probably the most popular in most western countries due to its richness and higher caffeine levels (roughly half of coffee, though in practice it depends entirely on how strong you make it).
Jasmine tea - Jasmine blossoms are a traditional Chinese flavor that is often infused into green tea, and sometimes other kinds, while curing. Jasmine offers a sweet aroma and, when properly infused, complements the natural tea flavor. Jasmine is the only really common infusion in China; American teas use lemon, mint and other flavors to counter the bitter taste tea gets when it's stale.