银本位是一种金融货币制度，它是以某一固定重量的银币或银块作为经济单位标准的。欧洲从拜占庭帝国灭亡（15世纪中叶）开始直至19世纪，都是使用银本位制度。 16世纪在南美洲西班牙殖民地（今玻利维亚）发现波托西银矿，西班牙大量铸造银币，称为比索（Peso），因为一比索等于八个皇冠币的价值，又称八片币（Pieces of eight）。自此银币成为这四百年间国际贸易通用的货币。

中国自汉代开始制造不少银器和银锭，但作为流通货币是由宋朝开始，在元朝时流行元宝，明朝时因为和西班牙、葡萄牙贸易，银币大量流通，亦使中国成为使用银本位的国家。

The silver standard is a monetary system in which the standard economic unit of account is a fixed weight of silver. The silver specie standard was widespread from the fall of the Byzantine Empire until the 19th century. Following the discovery in the 16th century of large deposits of silver at the Cerro Rico in Potosí, Bolivia, an international silver standard came into existence in conjunction with the Spanish pieces of eight. These silver dollar coins played the role of an international trading currency for nearly four hundred years.