"park ranger" is a broad title within the NPS. when i worked for them I got a badge and was told in a beginning-of-season meeting that "we're all rangers" even though i was in the science side of things and barely ever interacted with the public (we were supposed to wear the badge at work but i never did and neither did my coworkers). interpretive rangers are generally cool, they're the people who work at the visitor center, lead hikes, do talks about astronomy or wildlife, etc. they're usually either young people straight out of college or retirees volunteering. cop rangers can be real assholes individually but they don't kill people as often city cops, they do have a better "mission" and often assist in search and rescues and things like that. still they are law enforcement officers legally and i tried to avoid them and distrusted them for that reason, didn't want to get busted for smoking dope lol.