A conventional oven is a type of oven that has heating elements on the top and bottom of the oven cavity. The bottom heating element is the primary source of heat and is ideal for roasting large cuts of meat, like turkey or whole chickens. The upper heating element delivers intense top-down heat and works best for broiling and browning casseroles. In a conventional oven, the dish closest to an active heating element may cook the fastest. Conventional ovens circulate hot air using natural convection.

In contrast, a convection oven (also known as a fan-assisted oven or simply a fan oven) has fans to circulate air around food to create an evenly heated environment. The increased air circulation causes a fan-assisted oven to cook food faster than a conventional non-fan oven, which relies only on natural convection to circulate the hot air. Fan-assisted convection ovens are commonly used for baking as well as non-food, industrial applications. A convection oven allows a reduction in cooking temperature compared to a conventional oven, and the circulating air transfers heat more quickly than still air of the same temperature.

In summary, a conventional oven has heating elements on the top and bottom of the oven cavity and circulates hot air using natural convection, while a convection oven has fans to circulate air around food to create an evenly heated environment and cook food faster than a conventional non-fan oven.