[wikipedia] used either by purchasers of real property to raise funds to buy real estate; or alternatively by existing property owners to raise funds for any purpose, while putting a lien on the property being mortgaged
[dictionary] The usual way of calculating interest - as a percentage of the sum borrowed.
[mtgprofessor] how many years the borrower has to repay the mortgage
Adjustable Rate Mortgage
[investopedia] a mortgage loan with the interest rate on the note periodically adjusted based on an index which reflects the cost to the lender of borrowing on the credit markets
Fixed Rate Mortgage
[bankrate] A mortgage in which the monthly payment based on interest does not change