This question comes up frequently in my estate planning practice - "What's the difference between a Personal Representative/Executor and a Trustee?" The difference is important if your estate plan includes a Revocable Living Trust or any type of Irrevocable Trust. While Personal Representatives/Executors and Trustees are both types of fiduciaries, they'll play very different roles in your estate plan.
A Personal Representative, also called an Executor, is appointed by a probate judge to oversee the administration of a probate estate and can be a person, an institution, such as a bank or trust company, or a combination of both. If the decedent had a Last Will and Testament, then in most cases the probate judge will appoint the Personal Representative named in the Last Will. If the decedent didn't have a Last Will, then state law will dictate who the probate judge should appoint to serve as the Personal Representative, but the probate judge will make the final decision based on what the judge thinks is in the best interest of the estate's beneficiaries.
On the other hand, a Trustee is named by the person who creates a trust, called the Trustmaker, to oversee the day to day management of property owned by the trust for the benefit of the trust beneficiaries. As with a Personal Representative, a Trustee can be a person, an institution, or a combination of both. In the typical situation, the Trustmaker, Trustee and Beneficiary of a Revocable Living Trust are one in the same person. But if the Trustmaker becomes mentally incapacitated or dies, then a successor Trustee will need to step in to manage the trust property.