$BTC The U.S. dollar (USD) is the official currency of the United States and one of the most widely used currencies in global trade and finance. Recognized by its symbol "$" and ISO code "USD," it serves as the world’s primary reserve currency. Managed by the Federal Reserve, the dollar plays a crucial role in the global economy, influencing exchange rates, commodity prices, and international investments. It is used not only within the U.S. but also accepted or pegged in various countries. Strong demand for the USD reflects trust in the U.S. economy and its political and financial stability.