What is the difference between a biography and an autobiography?

The main differences between an autobiography and a biography are, first of all, biography is written by a person that studied a lot about another and a autobiography is written by himself/herself. Another main difference is that in a biography the author has to strictly study the persons life while in a autobiography

A biography is the story of a person's life in the words of another person, while an autobiography is the story of a person's life in his own words. A biography is typically written in third person, while an autobiography is typically written in first person. While an autobiography is usually written by the subject instead of another writer, some individuals hire a writer to assist with the document.