Market value is what the home could sell for within a reasonable time period. The appraised value might be lower since this takes into account what a typical purchaser would realistically be willing to pay for a home. So, while someone pays market value for a home and isn’t bothered by the railroad tracks behind the neighborhood, a typical buyer would not be as thrilled with that feature and pay much less.  Be sure to weigh the outside circumstances around the property in addition to the features inside.