You can see from our tea collection that there are several types of tea. Black, Green, White and Oolong teas all come from the same plant: the camellia sinensis (cousin to the garden camellia). Each tea looks and tastes different because of the way the leaves are processed.
Black tea leaves have been fully fermented (or oxidized), giving them their robust flavor and their higher level of caffeine.
Green tea has had little or no fermentation (oxidation) and has less caffeine than Black tea. It can vary from quite mellow in flavor to more "grassy" tasting.
Oolong is somewhere between Black and Green tea. It has had just enough fermentation for a darker exterior while the interior remains green, giving it a wonderfully complex flavor. Depending on how much oxidation has occurred, Oolongs will vary on a spectrum from almost green to almost black. They are sometimes described as "orchid-like" in taste.
White tea is made from only the tea plant's newest "downy" leaves. It has not been fermented at all but merely dried, so you'll often see little white hairs or down on the leaves. White tea has a very subtle flavor, and minimal caffeine.