Basics

Floating Aerators (Including both Floating Surface Aerators and Floating Brush Aerators ) which are mainly used for pond/lagoon aeration (for WWT or Aquaculture
Faucet Aerators (A Device Used to Introduce Air into a Faucets Water, and thus Reduce Water Waste for Handwashing applications without much apparent change in "felt volume")
Aspirators (More properly known as Vacuum Ejectors , which are Faucet Aerators optimized for creating a suction source

Aerator (Disambiguation Page)