Wet mopping and dry sweeping serve completely different floor needs

Dry-sweeping robot vacuums suck up dust and crumbs into a dustbin — that’s the classic robot vacuum experience. Wet-mopping robots add a water tank that sprays water and wipes floors at the same time. The distinction matters more than you’d think because they solve different problems. Dry sweeping handles the daily stuff: crumbs, pet hair, surface dust. Wet mopping addresses the film of grime that builds up on hard floors over time — the invisible layer that dry sweeping leaves behind. Most combo robots alternate between the two, but the mopping is a light damp wipe, not a deep scrub. If your home is mostly hard floors, the combo is worth it. If you have carpet wall-to-wall, skip the mop and invest in better suction.