There are several types of exchange rate systems used in international finance. Three common types are:

1. **Fixed Exchange Rate System**: In a fixed exchange rate system, the value of a currency is set or "fixed" in relation to another currency or a basket of currencies. The central bank or government actively intervenes in the foreign exchange market to maintain this fixed rate. This system provides stability but requires continuous central bank intervention to defend the fixed rate.

2. **Floating Exchange Rate System**: In a floating exchange rate system, exchange rates are determined by market forces of supply and demand. Governments and central banks do not actively intervene to maintain a specific exchange rate. Exchange rates can fluctuate freely based on economic conditions, trade balances, and other factors. This system allows for flexibility but can lead to exchange rate volatility.

3. **Managed Floating Exchange Rate System**: In a managed floating system, exchange rates are allowed to float, but central banks or governments occasionally intervene to influence or stabilize exchange rates. This intervention can include buying or selling currency in the foreign exchange market to manage the currency's value. Managed floating combines elements of both fixed and floating exchange rate systems.

These are the three primary types of exchange rate systems, but there are variations and hybrid systems as well, depending on the specific policies and interventions of countries and central banks.