There has been three major development in how tea is produced:
First the chinesee pressed the leaves together in to bricks. When they wanted to make tea they shaved of tea, and added other things to give it more taste.
Next the chinese started steaming the tea leaves just after picking the, and then drying them. This makes the leaves keep their fresh green color. After they had dried and been stored from may to november they grinded it into a fine powder. This is Matcha. Matcha disolves in water so that one actually drinks the entire leaf.
The last form of tea is the one we usually drink in the west where the leaves have been fermented then dried. When we drink this the water has only been absorbing some of the taste, and most of the leaf is thrown away.