Base currency is a term that refers to the currency used as a reference or base for foreign exchange transactions. It is the first currency listed in a currency pair and is also known as the accounting currency, domestic currency or primary currency. The base currency is crucial because it determines the value of the exchange rate relative to other currencies. In some cases, it is also known as the primary currency, reference currency, or home currency. Additionally, it is commonly referred to as the reporting currency as it is used to report financial statements. Overall, the term base currency refers to the currency that is used as the basis for all forex transactions.