What is Mortgage loan?

A long-term loan granted to buy a home or other real estate (or to obtain money secured on it), with that property pledged as collateral. The borrower may live in and use the property, but if the loan is not repaid, the bank has the right to satisfy its claim out of the pledged property. Usually the buyer pays part of the price from his own funds as a down payment and the bank provides the rest; the debt is repaid over many years with annuity or differentiated payments.

Source: Britannica Dictionary: mortgage; Mortgage (Wikipedia)