That’s a good question.
The long answer: “A debt instrument, secured by the collateral of specified real estate property, that the borrower is obliged to pay back with a predetermined set of payments. ” (Investopedia, 2015)
It short answer: it’s a loan backed by a home.
What kinds of mortgages are there? There are a number of options you’re best served by speaking directly to a lender on but there are some basic types such as a Veterans Affairs (VA) loan guarantee (also called VA loan), conventional loan, FHA loan, or an Adjustable Rate Mortgage (ARM).