Exchange rate is the exchange rate between different currencies.

There is a purchasing power parity. For example, a hamburger in McDonald's is 12 yuan RMB, which is about 2 US dollars. Then the calculated exchange rate is about 6: 1, which means that 6 yuan RMB can buy as much as 1 US dollars. This is the exchange rate.

Bank quotes generally have three prices, the buying price, the selling price and the middle price.

The purchase price is that the bank buys foreign exchange from you.

The selling price is that the bank sells you foreign exchange,

The median price refers to the average of two prices.

If the bank wants to make money, you sell it cheaply and you buy it expensively.