passenger vs traveler

passenger and traveler both are nouns.

Word	Noun	Adjective	Verb	Adverb
passenger	Yes	No	No	No
traveler	Yes	No	No	No

As nouns, traveler is a hypernym of passenger; that is, traveler is a word with a broader meaning than passenger:

passenger: a traveler riding in a vehicle (a boat or bus or car or plane or train etc) who is not operating it
traveler: a person who changes location

Other hypernyms of passenger include traveller.

passenger (noun)	traveler (noun)
a traveler riding in a vehicle (a boat or bus or car or plane or train etc) who is not operating it	a person who changes location