camping bus vs caravan

camping bus and caravan both are nouns.

Word	Noun	Adjective	Verb	Adverb
camping bus	Yes	No	No	No
caravan	Yes	No	Yes	No

As nouns, caravan is a hyponym of camping bus; that is, caravan is a word with a more specific, narrower meaning than camping bus:

camping bus: a recreational vehicle equipped for camping out while traveling
caravan: a camper equipped with living quarters

Other hyponyms of camping bus include van.

camping bus (noun)	caravan (noun)
a recreational vehicle equipped for camping out while traveling	a camper equipped with living quarters
	a procession (of wagons or mules or camels) traveling together in single file

camping bus (verb)	caravan (verb)
	travel in a caravan