Sweet corn also called sugar corn or simply corn. It is a variety of maize with a high sugar content. Sweet corn is picked when immature, prepared and eaten as a vegetable, rather than a grain. Sweet corn must be eaten fresh, canned or frozen, before the kernels become tough and starchy. The kernels are boiled or steamed. They are often used as a pizza topping or in salads. Corn on the cob is a sweet corn cob that has been boiled, steamed or grilled whole. It is used in soups, salads, curries and rice dishes.