You (the person who creates the durable power of attorney).
The person making the power of attorney.
The person who appoints another to make decisions for him or her under a power of attorney. Same as Patient.
As it relates to power of attorney, a principal is the person who is no longer able to make decisions so the attorney-of-fact is granted the power to make those decisions.
The individual signing the power of attorney to authorize another individual to legally make decisions for him or her.