A Treasury Bill, often referred to as a T-bill, is a short-term government debt security issued by the U.S. Department of the Treasury. T-bills are sold at a discount to their face value and do not pay interest in the traditional sense. Instead, the investor receives the full face value upon maturity, with the difference representing the interest earned. T-bills typically have maturities ranging from a few days to one year. They are considered a low-risk investment because they are backed by the full faith and credit of the U.S. government, making them a popular choice for conservative investors seeking a safe place to park their money.