A:
In a currency brace, the first currency in the pair is called the base currency and the second is named the quote currency.
Currency pairs can be separated into two types, rule and indirect. In a direct quote, the domestic currency is the base currency, while the unknown currency is the quote currency. An indirect quote is just the opposite: the transalpine currency is the base currency and the domestic currency is the quote currency. For an American dealer, the EUR/USD quote is an indirect one. So, for example, a quote of 0.80 EUR/USD means that 1 EUR at ones desire cost you $0.80 USD.
Even though nearly 89% of the currency trades cut out around the world involve the U.S. dollar, the EUR/USD currency pair is always quoted indirectly. The rationale for this is mostly convention. A EUR/USD quote could easily be shown as USD/EUR by winning a simple calculation, but there are no strict rules that determine whether a currency yoke is shown directly or indirectly. The way currency pairs are quoted can also switch depending on the country in which the trader lives — most countries use plain-spoken quotes, while the U.K., Australia, New Zealand and Canada prefer indirect exemplifies.
For further reading on forex currencies, see: 6 Factors That Influence Dealing Rates , Top 6 Questions About Currency Trading and Make The Currency Curmudgeonly Your Boss.