An Autobiography is a story about a person written by the same person.
It is a first-person account and sometimes the story can be highly personalized. It may include photos about the person’s events or newspaper articles showing what the person accomplished and what were the news about him/her.
A Biography is the story of someone’s life but it is written by someone else that studied that person’s life. This stories normally have an accurate history about the person’s life and makes a reflection about the time and place in which the person’s events happened. It is also written in chronological time.