An ocean carrier who performs all of the services of a carrier, but who does not own their own vessel(s). They operate by leasing or buying available space in containers and using their own House Bill of Lading to contract with customers.
An NVOCC is a transportation intermediary, similar to a Freight Forwarder, except that an NVOCC contracts directly with the shipper to transport containers but does not usually own warehouse space (as opposed to a freight forwarder, who acts as the shipper's agent to book the shipment for transport with a carrier, but will typically have access to their own warehouse space).
NVOCCs are not controlled or regulated, but they usually must register for a license in the country where they operate.
Freight Forwarder Bill of Lading