China currency is called the renminbi.
The renminbi is measured in yuan, which is what the currency is usually called (this is similar to the British sterling, which is usually called the pound).
One yuan is divided into 10 jiao. 1 jiao is then divided into 10 fen.
China currency comes in notes and coins. Notes are denominated in 1, 5, 10, 20, 50, and 100 yuan.
Coins are denominated in 0.1, 0.5, and 1 yuan.
China currency is only used in mainland China, and is not used in Hong Kong or Macau.