Tea is a plant that belongs to the camelia family. There are two main varieties of Camellia sinensis; sinensis, which has small leaves and is used for most Chinese teas and Japanese teas, and assamica with large leaves and used in most Indian teas.
Black tea is oxidized (sometimes called fermenting) which means that it is rolled, then kept in a warm humid environment and finally roasted to stop the oxidation. Green tea is roasted immediately to stop oxidization and rolled afterwards. White tea is rolled without roasting. Oolong tea, also called Wu Long or Wu Li tea, is semi-oxidized and encompasses a range of teas from green to black.
Black tea is oxidized (sometimes called fermenting) which means that it is rolled, then kept in a warm humid environment and finally roasted to stop the oxidation. Green tea is roasted immediately to stop oxidization and rolled afterwards. White tea is rolled without roasting. Oolong tea, also called Wu Long or Wu Li tea, is semi-oxidized and encompasses a range of teas from green to black.