The renminbi (RMB) is the official currency of China with the yuan being the unit of account. The renminbi (RMB) is the name of the currency traded onshore and offshore. China institutes capital controls that prevents the currency from flowing abroad and visa versa thus creating a separation between these two markets. If the RMB is traded offshore, mainly Hong Kong, it is referred to CNH, if it is traded onshore, mainland China, it is CNY. The RMB is one currency but trades at two different exchange rates depending upon where it is traded. In 2015 it became the world 5th most traded currency.