What's the difference between a steam mop and a steam-and-vacuum combo?

A traditional steam mop heats water into steam and uses a pad to clean and sanitize sealed floors. Combos like the Bissell CrossWave, Narwal S20 Pro, and Roborock F25 Ultra vacuum debris, wash, and (in some cases) apply steam in one pass. Reviewers say combos save time on mixed wet-and-dry messes but cost far more, are heavier, and require more maintenance of brushrolls and self-cleaning systems.