Gross payoff - Lender is paid the amount the property is sold for and Sellers are responsible for all closing costs.
 
Net payoff - Lender is paid the net proceed afer all closing costs are paid
 
Minimum payoff - Lender requires a specified minimum amount of proceeds
                             Seller may be entitled to the surplus proceeds and is usually responsible for all or a portion of
                             closing costs
                             Seller may have to bring in money to satisfy the Lender's minimum payoff requirement
 
Information courtesy of Title Guaranty