My mortgage closing forms mention a "security interest." What is a security interest?
The security interest is what lets the lender foreclose if you don't pay back the money you borrowed.
A security interest means that if you don't make the mortgage payments as agreed, or if you break your agreement with the lender, the lender can take your home and sell it to pay off the loan. You give the lender this right when you sign your closing forms. The document granting the security interest can be called by different names, but the most common names are "Mortgage" or "Deed of Trust."
Familiarize yourself with some of the key documents you will be signing at closing so that you know what to look for when you get them.