With the deepening of China's reform and opening up, more and more people go abroad to study and travel, and many Americans come to China for tourism or business. But the money Americans use in the United States is dollars, while the money China people use is RMB. Then when Americans come to China, they must change their US dollars into RMB before they can buy things and stay in hotels in China. This brings about the exchange rate problem between the US dollar and the RMB, or between the RMB and the US dollar, which is commonly referred to as the exchange rate problem.