What do the different cleaning levels on the HFD360 do?

The HFD360 has six cleaning levels: Level 1 (Sleep) for ultra-quiet nighttime use, Level 2 (Germ) which slows air movement for better capture of microscopic germs, Level 3 (General) for everyday dust and smoke reduction, Level 4 (Pet) for pet hair, dander, and odors, Level 5 (Allergen) optimized for reducing airborne pollens, and Level 6 (Max) for the fastest air cleaning when odors or particles are noticeably present. The unit always starts on the General Cleaning setting each time it is powered on. (Page 3)