A currency pair is a price quote of the exchange rate for two different currencies traded in FX markets: They are known as the base currency and the quote currency. The exchange rate of a currency pair indicates how much of the quote currency is needed to purchase one unit of the base currency.
Currency pairs are also known as forex pairs. If you buy a currency pair, you’re buying the base currency and selling the quote currency. The bid (buy price) represents how much of the quote currency you need to buy one unit of the base currency. If you sell the currency pair, you’re selling the base currency and buying the quote currency.
For example, GBP/USD is the currency pair for British pound sterling against the US dollar. In this scenario, GBP is the base currency and USD is the quote currency. If GBP/USD is trading at 1.3740, then 1.3740 dollars will buy you one pound.