Sencha literally means "roasted (煎) tea (茶)", however, the process by which sencha is created differs from Chinese green teas, which are initially pan-fired (and could probably therefore more accurately be called "roasted" teas). Japanese green tea is first steamed for between 15–45 seconds to prevent oxidization of the leaves. Then, the leaves are rolled, shaped, and dried. This step creates the customary thin cylindrical shape of the tea. Finally, after drying, the leaves are fired to aid in their preservation and to add flavor.
The initial steaming step imparts a difference in the flavor between Chinese and Japanese green tea, with Japanese green tea having a more vegetal, almost grassy flavor (some taste seaweed-like flavors). Infusions from sencha and other green teas that are steamed (like most common Japanese green teas) are also greener in color and slightly more bitter than Chinese-style green teas.
Sencha is very popular in Japan, and is drunk hot in the cooler months and usually chilled in the summer months.