A "flashback" is a narrative technique used in literature and film that interrupts the chronological flow of a story to revisit a past event. This device allows the audience to gain deeper insight into a character's background, motivations, or significant experiences that shape the current narrative. Flashbacks can be presented in various forms, such as memories, dreams, or visual sequences. They are commonly used in works by authors like Charles Dickens and filmmakers like Christopher Nolan to enhance storytelling and create emotional connections with the audience.