Answer:
The key answer could be Monetary Policy.
Step-by-step explanation:
Most countries these days follow a Floating exchange rate system which is driven by the market forces of demand and supply.
There are ways such as,
1. Regulating the market: One of the basic functions of central banks is to regulate economic activity by setting interest rates, it is also referred to as the key interest rate.
2. Managing foreign reserves: Depending on the reserves, central banks decide to buy or sell foreign currency in order to influence its value. They try to control the price of the currency in order to avoid undervaluation or overvaluation.
3. Controlling the supply of money: A central bank may issue or withdraw liquidity in the domestic currency in order to regulate the money in circulation. The currency and the economy it represents give it an international dimension.