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. Usually, this results in a dual by-line that includes both names.
Some of the most famous autobiographies include "The Diary of a Young Girl" by Anne Frank, "Night" by Ellie Wiesel and "Long Walk to Freedom" by Nelson Mandela. Famous biographies include "Steve Jobs" by Walter Isaacson, "John Adams" by David McCullough and "Team of Rivals: The Political Genious of Abraham Lincoln" by Doris Kearns Goodwin.