The US Dollar is the official currency of the United States and is represented by the symbol "$" or the code "USD." It is one of the most widely used currencies in the world and serves as a global reserve currency, meaning many countries hold it as part of their foreign exchange reserves. The dollar is issued by the Federal Reserve, the central bank of the United States. The US Dollar is divided into 100 smaller units called cents. It is used in various forms, including coins and paper bills, which come in denominations of $1, $5, $10, $20, $50, and $100. The dollar's value can fluctuate based on economic factors, including inflation, interest rates, and trade balances.