The United States Dollar (USD) is the official currency of the United States and one of the most widely used fiat currencies in the world. Issued by the Federal Reserve, the USD serves as the global reserve currency, playing a key role in international trade, finance, and investment. Known for its stability and liquidity, the US Dollar is commonly used as a benchmark for valuing other assets, including cryptocurrencies. In the crypto space, USD is often represented through stablecoins like USDT, USDC, and DAI, which maintain a 1:1 peg to the dollar, enabling seamless digital transactions and reducing volatility.