United States coins are pieces of currency used for everyday transactions in the United States. They come in various denominations, including pennies, nickels, dimes, and quarters. Each coin features unique designs that often represent important historical figures, symbols, or events. The U.S. Mint is responsible for producing these coins, ensuring they meet specific standards for weight and composition. Coins are made from different metals, such as copper, nickel, and zinc, which contribute to their distinct appearances and values. The designs on the coins can change over time, especially for commemorative issues. Collectors often seek out rare coins, making numismatics a popular hobby in the United States.