The main difference between the two teas is in how the leaves are prepared.
It may come as a surprise that green tea and black tea are both leaves of the same plant – the tea plant, Camellia sinensis. It’s the variety of plant and how the leaves are processed that determines which is which.
Camellia sinensis sinensis is typically used to make green tea and Chinese black tea, while Camellia sinensis assamica is grown to produce Assam (Indian) black tea.