In plain English
What Quote currency means
In EUR/USD, the U.S. dollar is the quote currency. A price of 1.0850 means one euro costs 1.0850 dollars. When the quote currency changes, the pair’s displayed rate changes even if the base currency amount stays one unit.
Why it matters
The quote currency tells you how much you pay or receive per unit of the base currency. It also matters for profit and loss because trading gains are usually denominated in the quote currency unless the account is converted.
Example
If USD/CHF is quoted at 0.8800, one U.S. dollar is worth 0.8800 Swiss francs. If the quote rises to 0.8850, the dollar became stronger relative to the franc.
Quick answers
Common questions
Is the quote currency always the currency I pay in?+
Not necessarily. It is the second currency in the pair, while your account currency may be something else.
Can the quote currency be the same as the base currency?+
No. In a standard pair, the two currencies are different.
Sources