A lot of this falls into the realm of nuance. One guy compares his Glock to HK or whatever, and describes the differences. Next guy compares his Glock 17 to his Glock 19. Next guy compares his Gen x 19 for example, to a different Gen. Finally, another guy compares his G prefix 17 to a K prefix one. A have a buddy with a half dozen Sig 226 pistols, and each has in his mind a different enough trigger that he has a different name for each.