Most rice is classified as either brown or white; the color is determined by the way the grain is processed. White rice is stripped of its outer husk, as well as its bran and germ. Brown rice has its bran and germ left intact, has more vitamins and fiber, a stronger flavor, and a chewier texture. It also takes longer to cook, and is more perishable, so it is best bought in smaller quantities and kept refrigerated. All rice is classified by grain size; the shorter the grain the more starchy it will be.
Short-grain rice has a short, plump, almost round kernel. The cooked grains are soft and cling together; short-grained rice is used for risotto and sushi.
Medium-grain rice (from the japonica strain) has a shorter, wider kernel (two to three times longer than their width) than long grain rice. The cooked grains are more moist and tender, and have a greater tendency to cling together than long grain.
Long-grain rice (from the indica strain) has a long, slender kernel that is four to five times longer than their width. The cooked grains are separate, light and fluffy.
(see The Nibble for more rice information)