An autobiography is an account of a persons life being written by that person. For an example: "She made it sound so amazing and adventurous when she talked about her childhood" Another example for an auto biography is lets say, a book about someone life written by that person. Kind of how a diary or a journal works. They are both similar to an autobiography, because its about the person life, and it was written by that person. (let me now if you couldn't understand this) I hope this is what you were looking for.
