Stablecoins bridge the gap between volatile cryptocurrencies and stable fiat money. Most are pegged one-to-one to a currency like the US Dollar and backed by reserves, though some use algorithms or crypto collateral to maintain their peg. They are widely used for trading, remittances, and as a safe harbour during market volatility, offering the speed and openness of crypto with far less price fluctuation. The quality and transparency of a stablecoin's reserves are key to its trustworthiness.