A. Shop vac pulls a small volume at high suction. It can pick up and transport heavy loads.
B. Dust collector pulls a large volume at low suction. It can gather light loads from a larger area.
C. Air cleaner moves a large volume with very low suction. It collects the airborne dust that got away from the vac and collector.
D. Respirator for dust and fumes that are not handled by the others.
E. Broom, leaf blower dustpan etc. For what the others all miss.
It would be helpful to have a chart listing a lot of vacs and collectors with their volume, suction and hp.