Prologues are an introduction to a story, often used to provide background information and set the stage for the main plot. They are typically found at the beginning of books, plays, films, and other works of literature. The term 'PROLOGUE' comes from the Greek word 'prologos, ' which means 'before word.' Prologues can also be used to introduce characters, themes, and settings, as well as to provide a glimpse into the future of the story.