Corn is one of the most widely consumed cereal grains. As a good source of antioxidant carotenoids, such as lutein and zeaxanthin, yellow corn may promote eye health. It's also a rich source of many vitamins and minerals. Corn is a tall annual cereal grass (Zea mays) that is widely grown for its large elongated ears of starchy seeds. The seeds, which are also known as corn, are used as food for humans and livestock and as a source of biofuel and can be processed into a wide range of useful chemicals.