A biography is a story of someone's life written by another person from a second or third person perspective, using facts and interpretation to present who the subject was and how they influenced the world. An autobiography differs in that it is written by the subject about their own life experiences from a first person perspective without outside influence on the story. Biographers research materials like diaries and letters to present an objective but not always perfectly balanced account, while an autobiography allows one to share their life story from their own point of view.