This document provides an overview of foreign exchange, including definitions, markets, exchange rate systems, and instruments of foreign payment. It defines foreign exchange as the currency of other countries and explains that foreign exchange markets allow countries to settle international debts. The two main exchange rate systems are fixed and floating rates. Under a fixed system the rate is set, while under a floating system the rate is determined by market forces. Common instruments for foreign payments include letters of credit, bills of exchange, bank drafts, and money orders. Exchange controls are implemented by governments to manage exchange rates and the balance of payments.