Memoir: a record of events written by a person having intimate knowledge of them and based on personal observation.*
Autobiography: an account of a person’s life written or otherwise recorded by that person.*
Many of us have a desire to sum up our lives, to leave a record for those who are to come; in fact, it is often a motivating factor in writing a book. But are you writing a memoir or an autobiography?
The definitions above don’t really make the distinction clear. In fact, I’ve found that most discussions on the subject often seem to be a bit vague on the difference. The best explanation I’ve heard is that an autobiography is a summing up an entire life. Often chronological, it includes research (yes, you even have to do research on your own life), and statements from other people. A memoir is a more personal recollection and emphasizes only events related to a specific theme or message.
So which are you writing? A memoir or an autobiography?
*source: dictionary.com