Distinction between aircraft class and type
Aircraft are all identified by manufacturer and model, or type: Robinson R22, Airbus A320, Cessna C172, etc. For some aircraft models, the qualification is specific (if I am qualified on the Boeing 737, I cannot fly the Boeing 747), and to switch from one to another it is necessary to attend an ab initio course (the type rating) which provides a different type of training for each type of aircraft depending on what is required by EASA regulations and by the manufacturer.