Why do ovens have fans?

Fan assisted ovens are convection appliances fixed with interior fans at the top and/or bottom, and a fan at the back to circulate the air round the interior which as a result keeps temperatures consistent when cooking. This circular air motion makes baking and roasting much easier, by ensuring that the contents are cooked faster, equally and consistently. The majority of fan assisted ovens give you the option to choose between fan or normal cooking programmes.