Food coupons are also known as free grocery coupons. Consumers have a way of adding titles to almost everything they use. But, the end result is the same. Exchange the coupon for cash off at the register. Some people have learned how to take multiple free coupons and exchange them at the register to lower their grocery bill from a big number to a little number. This means they walk out of the store with one or more carts of groceries for very little money.