Merriam-Webster defines a memoir as follows, “a written account in which someone (such as a famous performer or politician) describes past experiences, or a written account of someone or something that is usually based on personal knowledge of the subject.” So, how does that differ from a biography or an autobiography? Once again, turning to our expert above, a biography is the story of a real person’s life written by someone other than that person,” whereas, “an autobiography is the biography of a person narrated by himself or herself.” Obviously the lines can get blurred, but quite often, an autobiography spans a person’s lifetime whereas a memoir tells a story about a certain time period in someone’s life.