Tea in Japanese is お茶（ちゃ）(ocha) and if you ask for お茶 in Japan, you will probably get a cup of hot “green tea.” However, you may come across a package like the one in the photo and/or a menu item called グリーンティー written in Katakana in Japanese style cafés. Usually these グリーンティー and お茶 are quite different.
Depending on the ingredients and preparation methods, お茶 green tea is divided into several different kinds such as 煎茶（せんちゃ）, 玉露（ぎょくろ）, ほうじ茶（ちゃ）, 番茶（ばんちゃ）, 玄米茶（げんまいちゃ）, etc. If you compare them, they taste quite different. Some tea speciality shops will let you do “tasting.” If you like green tea, try it when you go to Japan!