A mutual fund is a type of investment that pools money from multiple investors to purchase a diverse portfolio of assets. One such type of mutual fund is a bond fund, which focuses on investing in bonds. Bonds are essentially loans made to companies or governments, and they come with a predetermined maturity date. A long-term bond fund, as the name suggests, primarily invests in bonds that take more than 10 years to mature. This means that the fund will hold these bonds until their maturity date, which can provide investors with a steady stream of income over a longer period of time.