Currency is the generic name given to countries’ money. Parity is the value of one currency against the currency of another. The first currency in the currency represents the base currency. The second written currency is the counter currency. The USD / JPY is the USD base exchange rate, while the JPY is the counter currency. The value of the USD / JPY parity is the value of the US dollar against the Japanese yen. For example; Assume that USD = 2, JPY = 1; USD / JPY will be worth 2 for the part. If the base is reduced, it will be equal to 1 USD = 2 Japanese yen. Central banks ‘monetary policies and economic developments can affect the value of countries’ currencies and create serious investment opportunities in currency parities.