Factory was the common name during the medieval and early modern eras for an entrepôt – which was essentially an early form of free-trade zone or transshipment point. At a factory, local inhabitants could interact with foreign merchants, often known as factors. First established in Europe, factories eventually spread to many other parts of the world. The origin of the word factory is from Latin factorium 'place of doers, makers'.

An entrepôt or transshipment port is a port, city, or trading post where merchandise may be imported, stored, or traded, usually to be exported again. Such cities often sprang up and such ports and trading posts often developed into commercial cities due to the growth and expansion of long-distance trade. These places played a critical role in trade during the days of wind-powered shipping. In modern times customs areas have largely made entrepôts obsolete, but the term is still used to refer to duty-free ports with a high volume of re-export trade. Entrepôt also means 'warehouse' in modern French, and is derived from the Latin roots inter 'between' + positum 'position', literally 'that which is placed between'.