What is the difference between wet mopping and dry sweeping robot vacuums?

Dry-sweeping robot vacuums suck up dust and crumbs into a dustbin, handling daily stuff like crumbs, pet hair, and surface dust. Wet-mopping robots add a water tank that sprays water and wipes floors, addressing the film of grime 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.