Expo (short for "exposition", an also known as World Fair and World's Fair) is the name given to various large public exhibitions held since the mid-19th century. The official sanctioning body is the Bureau International des Expositions (BIE), translated in English as the International Exhibitions Bureau (though sometimes rendered as the Bureau of International Expositions). BIE-approved fairs are divided into a number of types: universal, and international or specialized. They usually last between 3 and 6 months. In addition, countries can hold their own 'fair', 'exposition', or 'exhibition', without BIE endorsement.