Biologically, tea belongs to the class of Dicotyledoneae, the order of Theales, the family of Theaceae, and the genus of Camellia. There are about 500 recorded species of tea around the world. Due to its climate and geographical requirements (Read more in "Where did tea come from?"), tea trees are mostly distributed in the tropics and sub-tropics. China possesses the most numerous tea varieties amongst all tea producing countries, no less due to its long history of tea production and ideal growing habitats.
As we have learnt in "Where did tea come from?", different original varieties and processing methods have given rise to many types of tea leaves. Although there is currently no standard system to classify tea, as a general rule, tea is categorised into 6 basic groups and other processed varieties.