The type of unit you hold determines how any income generated from the fund's underlying investments is treated. With income units, income is paid out to fund holders as cash. This could provide the investor with an income stream or the cash could be reinvested to buy additional units. With accumulation units income is retained within the fund and reinvested, increasing the price of the units. Generally, for investors who wish to reinvest income, accumulation units offer a more convenient and cost-effective way of doing so.'.