The exposition is the portion of a story that introduces important background information to the audience; for example, information about the setting, events occurring before the main plot, characters' back stories, etc. Exposition can be conveyed through dialogues, flashbacks, character's thoughts, background details, in-universe media or the narrator telling a back-story. Alexander Bain and John Genung described exposition as one of four rhetorical modes of discourse, along with argumentation, description, and narration.