There are 4 main types of scrubbers: walk-behind scrubbers, sit-on scrubbers, sweeping scrubbers and single-disc scrubbers. Reverse scrubbers and sit-on scrubbers have water tanks and a water suction system. Single-disc scrubbers have only a scrubbing system, without water suction. Sweeper-scrubbers sweep and scrub the floor in one pass and suck up the dirty water directly.