Currency Pair
Currency pair represents the price of one currency quoted against the other. For example, BTC/USD is a currency pair. And the price of BTC is defined in terms of USD.
In a currency pair, the first listed currency is called the base currency, the second is the quote currency. So when we look at a currency pair, we see how much of the quote currency is needed to get one unit of the base currency.
Back to our example, BTC/USD = 9,340 means it takes $9,340 (quote currency) to get one BTC (base currency).
Make sure you understand how to read a currency pair quote to not get confused, especially when the ratios may not be as intuitive or currencies that familiar. For example, understanding the difference between the base and the quote currency is key when looking at crypto-to-crypto pairs. In LTC/BTC=0.0063, it takes 0.0063 BTC to get one LTC (and not the opposite!).