Explain the meaning of Mate's receipt?

A mate’s receipt is a receipt issued by the commanding officer of the ship when the cargo is
loaded on board and contains the information about the name of the vessel, berth, date of shipment, descripton of packages, marks and numbers, condition of the cargo at the time of receipt on board the ship, etc. The port superintendent, on receipt of port dues, hand over the mate’s receipt to the C&F agent.