Continuity editing is a system of cutting used to maintain clear narrative flow through a set of rules. It establishes spatial relationships and seamlessly flows shot sequences together. The key rules include the 180° rule to avoid crossing the line of sight between characters, shot/reverse shot editing between two characters, and re-establishing shots after a series of close-ups to reorient the viewer in a scene's location. Continuity editing creates structure, flow, and ease of viewing in films.