Mutual fund
A pooled fund priced once a day.
A mutual fund pools money from many investors and invests it in a portfolio of stocks, bonds or both.
Mutual funds vs ETFs
Mutual funds trade once a day at a price set after the market closes, while ETFs trade all day. Some mutual funds have minimum investments, and actively managed ones tend to charge higher fees.
Index mutual funds can be just as cheap as ETFs and are common in 401(k) plans.