Ozone generators create ozone at varying levels depending on output. It is heavier than air and needs a fan to get it up to ceiling level. The ozone claims to kill just about anything as it is also corrosive, harmful to pets and humans and can affect wiring, plants, plastics, soft rubber etc. It is an effective deodoriser and is also said to be highly effective as an antibacterial/antifungal. They work more slowly than foggers but leave no residual chemical when the area is properly ventilated after use. They are expensive compared to foggers. The cheapest can only output enough ozone to deodorise a small car. You will need an automatic timer to set the start and end time and leave an hour at the end of use before entering the treated area to give the ozone time to disperse.
Foggers work by forcing particles of atomised chemical into the air. The droplet size is controllable so can be varied to allow for suspended droplet size to one which soaks a substrate. They can be cold (ulv) or thermal. In practice ULV foggers are most commonly used for smoke damage, deodorising and antibacterial/antifungal application. Always wear a respirator when using a fogger (trust me an N95 dust mask is not enough). They are cheaper and offer a wider range of product application, from contaminant removal. insect treatment and odour control to soot suppression. They output a lot of water vapour so bear this in mind when using as you will need to dry out any treated room.
Thermal foggers are not really suitable for indoor use as their output leaves and oily residue on everything which is very hard to remove. They are usually used in severe smoke damage, greenhouses, animal housing and outdoors for insect, mould and pest control.