A trust deed or a deed of trust is a security instrument for real estate loans. In this case, the deed is a first lien on a property. The particulars of the loan are detailed in a separate promissory note, and the trust deed is recorded at the county recorder’s office. The trust deed serves legal notice to the world that the subject property is pledged to secure a loan. It also provides an accelerated foreclosure should a borrower default on a loan.