A power of attorney enables you to select who it is that you would want to handle your affairs in the event of your incapacity, as opposed to having the court decide this for you. The primary purpose of a power of attorney is to give one or more persons the legal authority to handle your assets on your behalf during your lifetime. Absent a power of attorney, if you become legally incompetent to handle your legal affairs and otherwise direct the disposition of your assets, the court would have to appoint someone to act on your behalf with respect to your property.
This court-appointed person is called a conservator. More often than not, the person appointed as your conservator is the person closest to you and the one you would want to serve in that capacity in any life-altering event, such as your spouse and/or one or more of your children.
Appointing a conservator before incapacity is a good idea. It avoids the related expense associated with having to go to court to have a conservator appointed and to have accountings filed with Commissioners of Account. The process can also avoid having a court declare you as being legally incompetent to handle your legal affairs, thereby depriving you of your right to make decisions on your own behalf.