People have used grasses for a long time. People eat parts of grasses. Corn, wheat, barley, oats, rice and millet are cereals, common grains whose seeds are used for food and to make alcohol such as beer.
Sugar comes from sugar cane, which is also a plant in the grass family. It is a plant with narrow leaves growing from the base. A common kind of grass is used to cover the ground in a lawn and other places.