Cereal crops or grains are mostly grasses cultivate for their edible grains or fruitseeds (i.e., botanically a type of fruit called a caryopsis). Cereal grains are grown in greater quantities and provide more energy worldwide than any other type of crop; they are therefore staple crops. They are also a rich source of carbohydrate. In some developing nations, grain in the form of rice or corn, constitutes practically the entire diet of poor people.. In developed nations, cereal consumption is both more moderate and varied but still substantial.