1, the spread is essentially the difference between the buying price and the selling price. Because traders tend to exchange one currency for another, foreign exchange trading currencies are usually quoted at the current price compared with another currency. For convenience, these currencies are written in pairs, such as AUD/USD (AUD/USD-where AUD is the "base currency" and USD is called "relative currency". )

2. For example, from the chart, the exchange rate between euro and dollar is 1.4502, while the exchange rate between dollar and euro is 1.4505, and the price difference between the two currencies is 0.0003.