It’s a special form of green tea
Matcha literally means “powdered tea.” When you order traditional green tea, components from the leaves get infused into the hot water, then the leaves are discarded. With matcha, you’re drinking the actual leaves, which have been finely powdered and made into a solution, traditionally by mixing about a teaspoon of matcha powder with a third cup of hot water (heated to less than a boil), which is then whisked with a bamboo brush until it froths.