A "Return Address" is the part of a letter or package that indicates where it should be sent back if it cannot be delivered to the intended recipient. It typically includes the sender's name, street address, city, state, and zip code. This information helps postal services efficiently manage undeliverable mail. Including a return address is important for both personal and business correspondence. It ensures that important documents, such as bills or invitations, can be returned if necessary. Additionally, it provides a way for recipients to contact the sender if needed, enhancing communication and accountability in mailing processes.