Green tea is kinds of tea made from Camellia Sintesis that has been through the process of heating to prevent oxidation. Green tea contains highest concentration of antioxidant called polyphenols. Green tea is usually brewed and drunk as a beverage. Green tea extracts can be taken in capsules and are sometimes used in skin products. Uses of green tea for consumption and medical purpose has been done long time ago by people in China, Japan, and India. Traditional medicine in China and India, used green tea as a stimulant therapy, diuretic (to promote excretion of urine), astringent (to control bleeding and help heal wounds) and to improve the health of the heart. Other traditional uses of green tea include treating flatulence (gas), the regulation of body temperature and blood sugar, promoting digestion and improve mental processes.
In Japanese culture, japan people always drink green tea or also known as Ryokucha as a tea. So if you offered tea (ocha) high possibility it is green tea. There are many types of green tea in Japan, such as Gyokuro, Matcha, Sencha, Genmaicha, and Kukicha.