"Cargo" is the generic term for anything being transported.
Cargo is usually considered to be raw materials or biological matter and is transported usually by starship in a cargo hold using containers and barrels. (citation needed • edit)
Cargo can refer to more than simply inorganic matter, however. Anything being transported is considered cargo and that can include sentient life forms. In 2368, an empathic metamorph named Kamala was cargo to the Enterprise-D before being disturbed from her cacoon early and then empathically bonding with Captain Picard. (TNG: "The Perfect Mate")