All varieties of rice can be divided into short-, medium- and long-grain varieties. All Italian rice  are strains of a thick, short-grained rice called japonica (Oryza sativa japonica). They may not, to most palates, taste different, but they do behave differently when cooked. There are four grades of rice:
Comune or originario
The cheapest, most basic rice, typically short and round, used for soups and desserts, but never risotto.
Semifino
This grade, of medium length, maintains some firmness when cooked. Risotto can be made with a semifino grade, although semifino is better employed in soups.
Fino
The grains are relatively long and large and taper at the tips. Fino-grade rice remains firm when cooked. Several varieties are commonly graded fino, including Vialone Nano, Razza 77, San Andrea, and Baldo.
Superfino
This grade represents the fattest, largest grains. They take the longest to cook, and can absorb more liquid than any of the others while still remaining firm. Superfino rices include Arborio and Carnaroli.
