Formula One, abbreviated to F1 is the highest class of open wheeled auto racing defined by the Fédération Internationale de l'Automobile (FIA), motorsport world's governing body. The "formula" in the name refers to a set of rules to which all participants and cars must conform. The F1 world championship season consists of a series of races, known as Grands Prix, held usually on purpose-built circuits, and in a few cases on closed city streets, the most famous of which is the Monaco Grand Prix in Monte Carlo. The results of each race are combined to determine two annual World Championships, one for drivers and one for constructors.