A deed of trust is unlike most other deeds which are used to transfer property. Instead, this document is a version of a mortgage note which is held by a trustee until the loan is satisfied. Most often the trustee is the title company.
When a deed of trust is used the property becomes collateral which can be repossessed if the borrower defaults on their note. The deed transfers the property title to the Trustee and assigns the bank as beneficiary. Trustees have authority to sell the property through a process known as 'foreclosure by power of sale'.
Trustees are an independent party separate from the lender. Banks, credit unions, or private lenders are listed as a secured creditor which offers them protection should the borrower incur mortgage default.