In the industry, it is the generic name for a temperature controlled container. The containers, which are insulated, are specially designed to allow temperature controlled air circulation within the container. A refrigeration plant is built into the rear of the container. For OOCL's reefers, power for this plant needs to be provided from an external source.
The reefer is a type of ship typically used to transport perishable commodities which require temperature-controlled transportation, mostly fruits, meat, fish, vegetables, dairy products and other foodstuffs.