I live in a state that is very unique.  Half of the state has deeds of trusts, the others have mortgages. There are only a handful of states that use mortgages and the majority use the deed of trust. The major difference lies after a person defaults. With a mortgage, the laws are different and the owner can buy back the home after the auction for the default has occurred.  While in a deed of trust the sale is the final piece to the house selling, which is why most states use it. 

I know that most people don't have to worry about the difference, but in states where both are used, which there are a few, it is important to know whether it is a mortgage or a deed of trust that a person is getting when they purchase a home.