>>520703252
They use natural convection, as well the other two heat transfer ways
But what we call convection ovens commercially are air flow assisted ovens. They just help the air move faster inside the oven and thus dry the surface of the food faster from all the released water vapours that are moved around and further heated around and usually end on an exhaust. You could also call them dry ovens and a dry oven is a particular tool of which derived the cheap commercially avaible air fryer or "convection" ovens. I believe they are also called "blast ovens".
Good for making tendies crunchy fast.