Grand Prix motorcycle racing refers to the premier class of motorcycle racing events held on road circuits sanctioned by FIM. Independent motorcycle racing events have been held since the start of the twentieth century and large national events were often given the title Grand Prix, The foundation of a recognised international governing body for motorcycle sport, the Fédération Internationale de Motocyclisme in 1949 provided the opportunity to coordinate rules and regulations in order that selected events could count towards official World Championships as FIM Road Racing World Championship Grand Prix. It is the oldest established motorsport world championship.
Grand Prix motorcycles are purpose-built racing machines that are generally unavailable for purchase by the general public or able to be ridden legally on public roads. This contrasts with the various production-based categories of racing, such as the Superbike World Championship and the Isle of Man TT Races that feature modified versions of road-going motorcycles available to the public.
The championship is currently divided into three classes: MotoGP, Moto2 and Moto3. All three classes use four-stroke engines. The 2018 MotoGP season comprises 19 Grands Prix, with 12 held in Europe, four in Asia, two in the Americas, and one in Oceania. - Source : MediaWiki