In answering a reader’s questions about book categories, LDS Publisher writes:
If your book is about a personal life experience or event, is in story form and written in first person, and follows what really happened very closely, it's a memoir (classified as non-fiction). (Example: Running with Angels by Pamela H. Hansen)….
If your book is based on a personal experience or event, written in first or third person, some liberty is taken with the facts to make it flow better or to hide the identity of certain participants, it's a novel based on true experiences (classified as fiction). (Examples: Torn Apart by Diony George; Room for Two by Abel Keogh)
For the record, Room for Two is a memoir, NOT “a novel based on true experiences”. LDSPublisher isn’t the first person to make that mistake and I’m not sure why some categorize it incorrectly. But it is a memoir so far as I understand the term.