When a shipowner, either directly or through an agent, undertakes to carry goods by sea, or to provide a vessel for that purpose, the arrangement is known as a contract of affreightment. Such contracts may take a variety of forms, although the traditional division is between those embodied in charterparties and those evidenced by bills of lading. Where the shipowner agrees to make available the entire carrying capacity of his vessel for either a particular voyage or a specified period of time, the arrangement normally takes the form of a charterparty.
On the other hand, if ship owner employs his vessel in the liner trade, offering a carrying service to anyone who wishes to ship cargo, then the resulting contract of carriage will usually be evidenced by a bill of lading. The two categories of charterparty and bill of lading are not,
however, mutually exclusive, since frequently the party chartering a vessel for a specific period of time may himself operate it as a general carrier.