How it differs from a dividend
While a stock dividend is paid out of a company's profit, a mutual fund's distribution includes investment income but may also, in some cases, be paid by drawing down part of the fund's own trust assets (its principal). The latter is called a "special distribution" (return of principal), and it differs in nature from profit generated through investment.
What to keep in mind
Evaluating a fund based on the size of its distributions alone can cause investors to overlook cases where the fund is effectively just returning its own principal. It is important to check the breakdown of distributions (the split between ordinary and special distributions) together with the trend in net asset value.
