A mortgage is a loan, but a loan specifically used to buy property or land.
The property or land purchased is then held as security for the loan. Which means it's part of the contract between you and the lender.
If you cannot repay the loan in the form of monthly repayments, the lender will take back (repossess) the property or land and would then typically sell it to get their money back.
Mortgage can be complicated, and there are many variations. It’s best to speak to a mortgage broker to find the right one for you.