A mortgage is the pleging of a property to a lender as a security for a mortgage loan. While a mortgage in itself is not a debt, it is evidence of a debt. It is a transfer of an interest in land, from the owner to the mortgage lender, on the condition that this interest will be returned to the owner of the real estate when the terms of the mortgage have been satisfied or performed. In other words, the mortgage is a security for the loan that the lender makes to the borrower.