An omniscient narrator in a novel is a narrator who knows everything about the characters and events in the story. This means that the narrator can provide insights into the thoughts, feelings, and motivations of the characters, as well as describe events and settings in detail. Unlike a detached narrator who stays separate from the story, an omniscient narrator has a more active role in the storytelling process. They can provide commentary, offer opinions, and guide the reader's understanding of the story.