What is a Promissory Note Secured By Deed Of Trust? The promissory note is a document that outlines the terms of the loan and the following procedure should the terms not be met.Real Property as Security for a Loan. The deed of trust is what secures the promissory note. Promissory note executed by. As maker, in favor of. The promissory note outlines the terms of the loan and the borrower's promise (hence the name) to pay. Once a loan is completely repaid, the promissory note will be marked "paid in full" and the deed will be returned to the buyer. A deed of trust is a type of secured real-estate transaction that some states use instead of mortgages. See State Property Statutes.