Answer: a biography is an account of someone's life written by someone other than the person's life it was about.
an autobiography is an account of someone's life written by the person who's life it is about. this is stupid, but i remember the difference by thinking 'auto' so the account was written 'automatically.' no one else had to do it (except for the person who's life it was about), it was automatic.
Step-by-step explanation:
thank you so much!!