Currency Pair — the relative value of one currency expressed in another currency. In other words, we can find out the value of one national currency by comparing it to the value of another currency. All currency pairs can be expressed in pre-defined combinations: EUR/SGD, UAD/CHF, GBP/CHF, USD/JPY, etc. Any transaction on the Forex market involves buying one currency and selling another. That is how the currency pair quotes are formed (which serve as the basis for trading).