The amount that investors pay when they buy (front-end load) or redeem (back-end load) shares in a mutual fund, similar to a commission. The SEC's rules do not limit sales loads a fund may charge, but FINRA's rules cap mutual fund sales loads at 8.5% of the purchase or sale, or at lower levels, depending on other fees and charges.

Source: http://investor.gov/glossary/glossary_terms/load#.Us7eqmRDuEg