jet fighter generations

Jet fighters can be categorized in generations. The Royal Australian Air Force Air Power Development Centre Bulletin, while not endorsed by the RAAF, notes the term appeared in the 1990s to make sense of the leap-frogging improvements in performance to jet fighter aircraft brought about through major advances in aircraft design, avionics, and weapon systems and proposes that a generational shift in jet fighter aircraft occurs when a technological innovation cannot be incorporated into an existing aircraft through upgrades and retrofits.