The official Chinese currency is the renminbi, and the basic unit of renminbi is the yuan. It is abbreviated as either RMB or CNY, for "Chinese yuan."
Renminbi is the official currency in all parts of the People's Republic of China except for Hong Kong and Macau. Hong Kong uses the Hong Kong dollar, and Macau uses the Macau pataca. The Macau pataca is backed by the Hong Kong dollar, which is in turn pegged to the U.S. dollar.
The official currency of Taiwan is the new Taiwan dollar. The basic unit of new Taiwan dollars is also called the yuan.