While tea from China comes in many colors including white, green, brown (oolong) and black, all tea from Japan is green. There are three main types of green tea from Japan.
Sencha is the most common tea served as an every day drink in Japan. While there are high-quality Sencha tea leaves that are plucked by hand and served only on special occasions, Sencha is generally the daily tea enjoyed by the Japanese people. Sencha is steamed immediately after it is picked to instantly stop the fermentation process. This same process is done with all Japanese green teas.
Gyokuro is the highest grade of Japanese tea. It is considered a luxury and made from only the first flush. The resulting brew is a pale, yellowish green color, and it has a rich flavor. The bushes from which the Gyokuro tea leaves are plucked are kept in the shade beginning in about May. As soon as the first buds sprout, the entire crop is covered with mats, which reduce the light and force the tea leaves to produce a higher chlorophyll content. The reduced light results in a darker green tea leaf with lower tannins, which gives the tea a sweet, mild flavor. Just like the Sencha tealeaves, the Gyokuro tealeaves are immediately steamed to stop fermentation.
The final green tea is Matcha, which is a green powder made from grinding Gyokuro tealeaves. This powder is whisked in a bowl of hot water to make a frothy tea flavored drink. This it the tea that is traditionally used in cooking and is served in the traditional Japanese Tea Ceremony. Since this drink is made with a powder you are actually drinking the ground tealeaves, so Matcha has the highest concentration of vitamins, anti-oxidants and catechins of any green tea.