Matcha is green tea or more specifically, a powdered green tea, more concentrated than the tea leaf version. For the last few weeks of the growing cycle, the tea is grown without direct sunlight. This causes a tremendous increase in chlorophyll production, a great detoxifier (heavy metals, chemical toxins). It is harvested & steamed quickly to prevent oxidation (retain color, prevent loss of antioxidants). The leaves are dried & made into a powder. Matcha has been consumed for centuries in the Asian culture but has found popularity in the West more recently due to claimed health benefits.