In the broad sense, "free port" means any part of a nation's territory that is divided off by whatever means from the rest of its territory, and exempted from customs formalities and the collection of customs duties. In the narrow sense, a free port has to be located within the area of a specific port.
廣義的自由港是指在本國國土中，用一定方式與其他地區做出區隔，以免除海關手續和關稅納徵等規範的區域；而狹義的自由港則必須侷限在特定的港區範圍內。