A currency pair is the quotation of the relative value of a currency unit against the unit of another currency in the foreign exchange market. The currency that is used as the reference is called the counter currency, quote currency or terms currency and the currency that is quoted in relation is called the base currency or transaction currency. The most traded currency pairs in the world are called the Majors. They involve the currencies euro, US dollar, Japanese yen, pound sterling, Australian dollar, Canadian dollar, and the Swiss franc.