autobiography vs life story

autobiography and life story both are nouns.

Word	Noun	Adjective	Verb	Adverb
autobiography	Yes	No	No	No
life story	Yes	No	No	No

As nouns, life story is a hypernym of autobiography; that is, life story is a word with a broader meaning than autobiography:

Other hypernyms of autobiography include biography, life, life history.

autobiography (noun)	life story (noun)
a biography of yourself	an account of the series of events making up a person's life