As a literary genre, a memoir (from the French: mémoire from the Latin memoria, meaning "memory", or a reminiscence), forms a subclass of autobiography – although the terms 'memoir' and 'autobiography' are almost interchangeable in modern parlance. Memoir is autobiographical writing, but not all autobiographical writing follows the criteria for memoir, as listed here. The author of a memoir may be referred to as a memoirist.
Memoirs are structured differently from formal autobiographies which tend to encompass the writer's entire life span, focusing on the development of his/her personality. The chronological scope of memoir is determined by the work's context and is therefore more focused and flexible than the traditional arc of birth to childhood to old age as found in an autobiography.
Memoirs tended to be written by politicians or people in court society, later joined by military leaders and businessmen, and often dealt exclusively with the writer's careers rather than their private life. Historically, memoirs have dealt with public matters, rather than personal. Many older memoirs contain little or no information about the writer, and are almost entirely concerned with other people. Modern expectations have changed this, even for heads of government. Like most autobiographies, memoirs are generally written from the first person point of view.
Gore Vidal, in his own memoir Palimpsest, gave a personal definition: "a memoir is how one remembers one's own life, while an autobiography is history, requiring research, dates, facts double-checked." It is more about what can be gleaned from a section of one's life than about the outcome of the life as a whole.
Humorist Will Rogers put it a little more pithily: "Memoirs means when you put down the good things you ought to have done and leave out the bad ones you did do."
Contemporary practices of writing memoirs for recreational, family or therapeutic purposes are sometimes referred to as legacy writing or personal history. Such products may be assisted by professional or amateur genealogists, or by ghostwriters.
Memoirs have often been written by politicians or military leaders as a way to record and publish an account of their public exploits. In the eighteenth century, "scandalous memoirs", allegedly factual but largely invented, were written (mostly anonymously) by prostitutes or libertines: these were widely read in France for their vulgar details and gossip. In another vein, the rhetor Libanius framed his life memoir as one of his orations, not the public kind, but the literary kind that would be read aloud in the privacy of one's study. This kind of memoir refers to the idea in ancient Greece and Rome, that memoirs were like "memos," pieces of unfinished and unpublished writing which a writer might use as a memory aid to make a more finished document later on.
Women writers have been prominent amongst those combining the memoir form with historical non-fiction writing. Examples include Jung Chang's Wild Swans,Heda Margolius Kovaly's Under a Cruel Star and Helen Epstein's Where She Came From.
Some professional contemporary writers such as David Sedaris and Augusten Burroughs have specialised in writing amusing essays in the form of memoirs. To some extent this is an extension of the tradition of newspaper columnists' regular accounts of their lives. (Cf. the work of James Thurber which often has a strong memoir-like content).
With the expressed interest of preserving history through the eyes of those who lived it, there are many organizations that work with potential memoirists to bring their work to fruition. The Veterans History Project, for example, compiles the memoirs of those who have served in a branch of the US Military - especially those who have seen active combat. Many public libraries give Memoir Writing classes that are geared towards senior citizens and some autobiographical service companies periodically publish memoir collections featuring clients that participated at no cost.