In economics, the word cargo refers in particular to goods or produce being conveyed—generally for commercial gain—by water, air or land. "Freight" is the money paid to carry cargo. "Cargo" was originally a shipload. Cargo now covers all types of freight, including that carried by rail, van, truck, or intermodal container. The term cargo is also used in case of goods in the cold-chain, because the perishable inventory is always in transit towards a final end-use, even when it is held in cold storage or other similar climate-controlled facility. The term freight is commonly used to describe the movements of flows of goods being transported by any mode of transportation.