A mutual fund is a group of different investments, like stocks, bonds, and other assets, that are all managed by the same company. When you invest in a mutual fund, you are giving the company money, which then gets used to buy these different investments. The company pays professional people to watch the investments, so they make sure the investments are doing well. Then, when the investments go up, you make money too, because the value of your mutual fund goes up. So, when you invest in a mutual fund, your money is safe from any bad changes in the stock market, because the company is taking care of it for you.