Load funds charge a sales commission, usually in the form of a percentage on the amount of new money you add to the fund. Others charge a commission when you sell the fund. Load funds are usually offered by brokerage firms. Advocates of load funds argue that the sales commission is justified by the fund's superior performance. Sometimes the fees on load funds are waved for retirement accounts.
Annual expenses are the percentage of the fund's value spent managing the fund.
High expenses reduce the amount of your money that's put to work. Index funds generally have the lowest expense ratios. Some mutual funds give investors a choice of how to pay commissions, by offering different classes of shares. While one class of shares has a load, another class of the same fund is no-load. The different classes may also have different yields, annual expenses, and sales restrictions.