Following the example of the Euro dollar - EUR / USD, we find the Euro - EUR in first position being thus the base currency, while the dollar - USD (US dollar) is the currency quoted. The first currency of this pair is called the base currency, and the second currency of this pair is called the quoted currency. In the list located on our MT4 trading station, we find not only the most liquid currency pairs but also the prices of these same forex currency pairs.
For example, we can see that the price of the euro dollar - EURUSD is around 1.6500
This means that you need 1.6500 units of the quoted currency to obtain a unit of the base currency. In other words, for 1.6500 US dollar you can buy one euro at this moment. This is how forex currency pairs work.