Currency pairs can be separated into two types, direct and indirect. In a direct quote, the domestic currency is the base currency, while the foreign currency is the quote currency. An indirect quote is just the opposite: the foreign currency is the base currency and the domestic currency is the quote currency. For an American trader, the EUR/USD quote is an indirect one. So, for example, a quote of 0.80 EUR/USD means that 1 EUR would cost you $0.80 USD.
Even though nearly 89% of the currency trades made around the world involve the U.S. dollar, the EUR/USD currency pair is always quoted indirectly. The reason for this is mostly convention. A EUR/USD quote could easily be shown as USD/EUR by making a simple calculation, but there are no strict rules that determine whether a currency pair is shown directly or indirectly. The way currency pairs are quoted can also vary depending on the country in which the trader lives – most countries use direct quotes, while the U.K., Australia, New Zealand and Canada prefer indirect quotes.