A financial power of attorney, also called a FPOA, is a document for every person over 18 year where one person appoints another person to act on their behalf with respect to certain finance and business matters:
You want to give someone permission to act on your behalf      
You want to appoint an agent to manage your financial, business, real estate, or other personal affairs      
You want your agent to have the power to act for you if you become incapacitated and can no longer speak for yourself