the difference between Japanese AND Chinese Green Teas

the main difference are in Processing and Varieties

Processing:
         Stopping oxidation, the key step in producing a fine green tea, is done differently. Each method has its advantages and disadvantages.Chinese — mainly roasting (with some exceptions), a method that imparts a nice smell and enables makers to shape the teas; also oven dried and sometimes steamed. Often, methods are combined. Examples: Houkui (wholly ovened); Biluochun (roasted then ovened); Zhuyeqing (all three methods).Japanese — mostly steaming, making the tea greener and thus more attractive but grassy tasting; also some pan-roasting.

Varieties:
         Without a doubt, there are far more varieties of Chinese green teas than Japanese. They come in about nine shapes, including rolled into tight balls (Gunpowder) and looser balls (Dragon Pearls), or gently curled to then uncurl in your cup or teapot while steeping (White Monkey Paw). Some have Jasmine added, while others have flowers and fruits in them.Chinese Dragon Pearls Teas vary by the location where they’re grown. China grows tea in 15 provinces and so is more geographically diverse than Japan, with the taste varying accordingly. Chinese teas are also more likely to be hand-processed instead of made in a factory. The top Chinese green tea is Dragonwell, so popular that fake Dragonwell has entered the market (made from teas not grown in the Dragonwell area of China).Japanese teas come mainly in two types: needle-shaped pieces (Gyokuro and Sencha) and powder (Matcha). Some of these teas can taste fishy, especially if not properly processed. Not an issue if you like sushi. Some (pan-roasted) can taste nutty and go well with stir-fried foods. Sencha mixed with roasted rice is one of the most popular teas in Japan (Genmaicha), with good reason. It’s toasty tasting yet smooth and slightly sweet. Houjicha is a roasted green tea that is nutty in flavor with a brown liquid.