Personal representative is Arizona's term for the person other states call an executor: the one appointed to administer a deceased person's estate through probate. Named in the will, or appointed by the court when there is no will.
The job is real work with legal duties attached: inventory every asset, notify creditors and heirs, keep the house insured and the taxes paid, defend the estate if disputes arise, file the returns, and distribute what remains - all under fiduciary standards, with personal exposure for getting it wrong. Arizona also requires non-licensed representatives to complete a training program before serving.
Choosing this person is one of the two or three decisions that matter most in a will. Choose for reliability under pressure, not for seniority or hurt feelings.
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Educational information only, not legal advice. Terms have statutory details beyond these summaries - confirm your situation with a licensed professional.