Dollars are a form of currency used primarily in the United States and several other countries. They are represented by the symbol $ and come in various denominations, including coins and paper bills. The value of a dollar can fluctuate based on economic factors, such as inflation and exchange rates. The U.S. dollar is managed by the $Federal Reserve, which regulates the money supply and interest rates. It is also widely used in international trade, making it a key global currency. Many countries hold reserves of dollars to stabilize their own economies and facilitate trade.