Docking stations do more than just charge — some wash and dry too

At minimum, a docking station charges the battery — which is useful but nothing special. The advanced ones are where it gets interesting: they empty the robot’s dustbin into a sealed bag, wash and dry the mop pads with water and warm air, and refill the water tank. You don’t touch anything for weeks. The basic ones just charge; the expensive ones do everything but pour your coffee.