A factory ship, also known as a fish processing vessel, is a large ocean-going vessel with extensive on-board facilities for processing and freezing caught fish or whales. Modern factory ships are automated and enlarged versions of the earlier whalers, and their use for fishing has grown dramatically. Some factory ships are equipped to serve as a mother ship.

Trawling is an industrial method of fishing that involves pulling a fishing net, that is heavily weighted to keep it on the seafloor, through the water behind one or more boats. The net used for trawling is called a trawl. This principle requires netting bags which are towed through water to catch different species of fishes or sometimes targeted species. Trawls are often called towed gear or dragged gear.