A memoir (from French: mémoire: memoria, meaning memory or reminiscence) is a collection of memories that an individual writes about moments or events, both public or private, that took place in the subject's life. The assertions made in the work are understood to be factual. While memoir has historically been defined as a subcategory of biography or autobiography since the late 20th century, the genre is differentiated in form, presenting a narrowed focus. A biography or autobiography tells the story "of a life", while a memoir often tells "a story from a life", such as touchstone events and turning points from the author's life. The author of a memoir may be referred to as a "memoirist."