A fan oven, generally referred to as a convection oven, differs from typical conventional ovens by the way it operates. In a conventional oven, heat is poured into the oven cavity and left to spread on its own, which often results in unevenly distributed heat.
Convection ovens, on the other hand, use fans to force air around the oven cavity. Not only does this help to distribute the heat evenly, but it also helps foods cook faster. Because the air is rotated via a fan in the back of the oven, foods do not need to be rotated while cooking either.