In china, what is there offical currency and how is it dispersed and exchanged among people?

the currency is the RMB but the real issue is that china is rampant with counterfeiting. everyone checks their money before accepting it, even just 10rmb bills. counterfeiting is so common in china that even banks often give customers fake money without knowing it. unfortunately credit cards are not common in china, so we have to continue to deal with counterfeiting.