A freight train, also called a goods train or cargo train, is a railway train that is used to carry cargo, as opposed to passengers. Freight trains are made up of one or more locomotives which provide propulsion, along with one or more railroad cars (also known as wagons) which carry freight. A wide variety of cargos are carried on trains, but the low friction inherent to rail transport means that freight trains are especially suited to carrying bulk and heavy loads over longer distances.