When goods are made to inventory, they are usually stocked in a warehouse or distribution center. Whether they are ordered from the plant or the distribution center, the goods need to be transported to the store. A variety of carriers are used to transport the grocery products to the store: trucks, airplanes, trains and boats. Supermarkets may have their own fleet of trucks to transport goods, and supplements its shipping with common air, land and water carriers. They may also have a state-of-the-art distribution center.