An air fryer uses convection heat that circulates to cook food. It has rapid air technology instead of a heat-producing element (like electricity or gas) to operate. This appliance is suitable for frying simple meals without using oil. However, its cooking space is significantly smaller than an oven.
On the other hand, an oven works by producing heat from electricity or gas. The heat is slowly dispersed inside the oven to cook food. An oven is suitable for baking a wide range of dishes. However, it's not the most versatile appliance out there. It can't do multiple cooking styles like stewing, steaming and broiling, which some air fryer models do.