A carrier is the party that actually moves the freight — a trucking company or an owner-operator available for hire. Carriers range from a single truck to large fleets, and they haul either on the spot market or under ongoing contracts.
The carrier sits between the shipper (who owns the goods) and the receiver, and takes on responsibility for the load once it’s picked up. When a shipper or broker vets and approves one ahead of time, it becomes an authorized carrier for their freight.