Power of sale is the clause in a deed of trust that lets the trustee sell the property to satisfy the debt after a default, without first getting a court judgment. It is what makes non-judicial foreclosure, like Tennessee's trustee's sale process, possible, in contrast to states that require a lender to foreclose through a lawsuit.
Why it matters
This clause is why a foreclosure in Tennessee can move on a set notice period rather than a court's calendar.
In Tennessee: Tenn. Code Ann. § 66-8-101. This can work differently in another state.
General information, not legal or tax advice.