The yen is the official currency of Japan, symbolized by ¥. It is one of the most traded currencies in the world and is used in various financial transactions both domestically and internationally. The yen is subdivided into smaller units called sen, although sen is rarely used in everyday transactions. Introduced in 1871, the yen was part of Japan's modernization efforts. The currency is issued by the Bank of Japan, which manages its supply and value. The exchange rate of the yen can fluctuate based on economic conditions, trade balances, and monetary policy decisions.