Legal Definition
A security interest is a legal right granted to a creditor (such as a lender) over a debtor's assets, which provides the creditor with a legally enforceable claim against those assets, typically to ensure repayment of a debt or obligation.
Plain-English Translation
Imagine a special right that says you have the right to claim something from someone else's property. This is like saying, 'This house belongs to the bank because they have a right to take payment from it.'