The type I have is basically a fancy toaster oven that has convection, that is an internal fan. I had a toaster oven with "convection bake" setting but the air fryer has more controls, and 2 levels of fan speed. There are other configurations of "air fryers" and some seem incompatible with coffee roasting. So in this article I am referring to the toaster oven type with a glass front-facing door.