from web site
Forex trading is based on the exchange rate between two currencies. The exchange rate represents the value of one currency relative to another. For example, if the exchange rate between the US dollar and the euro is 1.10, it means that one US dollar is worth 1.10 euros.
Traders make money in forex trading by buying a currency at a lower price and selling it at a higher price. For example, if a trader believes that the value of the euro will increase relative to the US dollar, they can buy euros with US dollars. If the value of the euro does indeed increase, they can sell the euros back to the market for a profit. This can be one of the best time to trade Forex.