A shopping cart (carriage, buggy, trolley, or wagon) is a cart supplied by a shop, especially a supermarket, for use by customers inside the shop for transport of merchandise to the check-out counter during shopping, and often to the customer's car after paying as well. Often, customers are allowed to leave the carts in the parking lot, and store personnel return the carts to the shop. It's fun to race around supermarkets with these.