A power of attorney refers to legal authorization granted to an individual or group to act on someone's behalf, especially in making decisions or performing certain actions. There are several synonyms that are often used interchangeably with the term power of attorney, including: letter of attorney, mandate, proxy, authorization, delegation, agency, and representation agreement. Most of these terms are commonly used in legal documents and agreements that intend to spell out the limits and scope of the authority granted. Regardless of the synonym used, a power of attorney is an essential tool that allows someone to act on another's behalf in specific legal matters.