Currency pairs are the foundation of forex trading. A currency pair consists of two currencies, with one being bought and the other sold. The first currency is called the base currency, and the second one is the quote currency. For example, in the EUR/USD pair, EUR is the base currency, and USD is the quote currency. Understanding currency pairs and how they work is essential for traders. Major pairs like EUR/USD, GBP/USD, and USD/JPY are commonly traded and have tight spreads, making them popular among traders.