A mortgage is an agreement to give up an interest in something if you fail to perform some duty. In many cases, it means that you'll give up your home if you fail to repay your home loan as agreed. You can use mortgage as a verb, meaning "to pledge".
Mortgage and "home loan" are often used interchangeably. However, the mortgage is really the agreement that makes your home loan work -- the bank wouldn't lend you hundreds of thousands of dollars unless they knew they could claim your home in the event of your default.
I had to mortgage my home to pay for my child's education.