Green teas, like black teas and oolongs, have several broad categories, with their respective characteristics. The 6 most common categories are matcha, sencha, gyokuro, hojicha, genmaicha, and bancha. 

Matcha
After the harvest, the tea leaves are simply separated, dried, and powdered. Rather than infusion, the liquor is prepared by dissolving the powder in a small quantity of water, using a special whip. This results in a somehow foamy liquor (as can be seen on the opposite picture). Because the leaves are powdered and entirely dissolved, all the nutrients they contain are retained in the drink, which is a great merit of matcha, compared with teas brewed by infusion.

Matcha tea gardens receive special care. The plants are  covered for some time before harvest to control exposure to sunlight. This results in special sweetness and aroma, caused by the formation of amino acids.

Matcha is the tea used in sado, the traditional Japanese tea ceremony. Normally, a concentrated liquor, to be used by several persons in turns, is made. That type of drink is known as koicha. New buds from old trees are the best for koicha. Progressively, however, a less concentrated liquor is made for individual use. That one is referred to as usucha.

Gyokuro
Gyokuro tea plants also are covered for some time before the harvest, so they produce amino acids that sweeten the taste of the liquor, like matcha. In fact, the main difference from matcha is that the leaves are rolled after steaming. Gyokuro has a deep and strong taste. To get the best Gyokuro drink, the water should be boiled and cooled at around 50 degrees. For easier preparation, our company has developed a new gyokuro (Netto Gyokuro) that can be brewed with hot water.

Sencha
This is the typical as well as the most common green tea in Japan. Unlike matcha and gyokuro, the plants are not covered. From sencha, several other 
categories are made, either by treatment of the leaves or addition of other ingredients.

Sencha has two subdivisions: asamushi and fukamushi. The difference between the two is in the steaming method. As the name indicates, asamushi sencha is "light- steamed" (30 seconds to 1 minute), while fukamushi, or "deep-steamed," is steamed for a longer time (1 - 2 minutes). As a result of the deep steaming, the leaves of fukamushi sencha break apart easily  (as appears on this picture), and the liquor has less aroma. Nonetheless, it has a fuller taste and can be brewed in hot water, thus quicker.

Asamushi sencha is by and far the most commonly used. Actually. fukamushi sencha was introduced only around 40 years ago. It got a momentum during the 1964 Tokyo Olympics.

Genmaicha
It is made by adding roasted unpolished rice (genmaicha) to sencha.

Hojicha
It is made by roasting sencha of  the 1st and 2nd flushes usually. It is possible to use the large leaves or add kukicha (twig teas). The main feature of hojicha is its strong aroma. 

Bancha
Bancha is ordinarily made of 3rd flush and 4th flush leaves, which are steamed dry and finally roasted. This tea is boiled directly in the kettle and then served. Containing less caffeine, it is an excellent drink for children, sick people, and the elderly.