Currency refers to the money used in different countries for transactions. Each country typically has its own unique currency, such as the US Dollar in the United States, the Euro in many European Union countries, and the Yen in Japan. These currencies can vary in value and are often exchanged at different rates in the global market. The value of a currency can be influenced by various factors, including economic stability, interest rates, and inflation. People often exchange currencies when traveling or conducting international business, using services like banks or currency exchange offices to convert their money into the local currency of their destination.