Local foreign exchange is an indicator of the foreign exchange quota granted by the state to local governments, that is, the state grants local governments the right to use this quota of foreign exchange. In actual use, it needs to be purchased from China Bank in RMB. Foreign exchange transactions in the busiest places in the world are generally concentrated in financial institutions such as commercial banks. The purpose of buying and selling foreign exchange is to pursue profits. The way is to buy cheap and sell expensive, and earn the bid-ask difference.