Major and minor currencies
The eight most commonly used currencies in foreign exchange transactions (US dollar, euro, Japanese yen, British pound, Swiss franc, Canadian dollar, New Zealand dollar, and Australian dollar) are called major currencies, which is the most liquid and most commonly used. All other currencies are called secondary currencies.
The base currency is the first currency in any currency pair. Currency quotes show the value of the base currency when measured against the second currency. For example, if the USD / CHF rate is equal to 1.6350, then 1 USD is worth 1.6350 Swiss francs.
In the foreign exchange market, the US dollar is generally regarded as the “base” currency in the quotation, that is, in the quotation of the currency pair, the currency of the quotation unit is 1 US dollar to exchange with other currencies. The main exceptions to this rule are pounds, euros, Australian dollars and New Zealand dollars.
The quote currency is the second currency in any currency pair. It is usually called a spread currency, and any unrealized profits or losses are reflected in the currency.