Black tea appeared in the Qing Dynasty. Incidentally “black tea” was translated into Chinese as “red tea”, which is perhaps a more accurate description of the color and gradually people have accepted the translation. This tea is made from leaves more heavily oxidized than the green variety, and it is generally more flavorful.

What is green tea? Green tea is tea that has undergone minimal oxidation during processing. It is popular in China and Japan, and recently has become popular in the West, where people formally drink only black tea. The main difference between green tea and black tea is that green tea keeps the original color of the tealeaves without fermentation during processing, there as black tea is fermented before baking.

This article by Yang Tianqing and Daniel Kister.