In special economic zones[1][2] business and trades laws differ from the rest of the country. The term, and a number of other terms, can have different specific meanings in different countries and publications. Often they have relaxed jurisdiction of customs or related national regulations. They can be ports or other large areas or smaller allocated areas.
Terms include free port (porto Franco), free zone (zona franca), bonded area (US: foreign-trade zone), free economic zone, free-trade zone, export processing zone and maquiladora.
Most commonly a free port is a special customs area or small customs territory with generally less strict customs regulations (or no customs duties or controls for transshipment). Earlier in history, some free ports like enjoyed political autonomy. Many international airports have free ports, though they tend to be called customs areas, customs zones, or international zones.