What is a diffuser and how does it work?
Diffusers work as an atomizer turning larger drops of oils into tiny little droplets that come out as a fine mist. This mist is infused into the air by the diffuser. This process of atomizing can be done with or without water. Doterra offers both kinds of diffusers. Here is a link to a pdf page comparing the different kinds of essential oil diffusers DoTerra offers: doterra-diffuser-comparison (1).
Water diffusers can double as a humidifier and typically use less oil.
Waterless diffusers put out a more potent mist and can cover a larger area and the scent tends to last longer. They use more oil than their water-using counterparts.
Other searched for terms: Oil diffuser, aroma diffuser