Formula One (also Formula 1 or F1) is the highest class of single-seat auto racing that is sanctioned by the Fédération Internationale de l'Automobile (FIA). The FIA Formula One World Championship has been the premier form of racing since the inaugural season in 1950, although other Formula One races were regularly held until 1983. The "formula", designated in the name, refers to a set of rules, to which all participants' cars must conform.