spacecraft vs orbiter

spacecraft and orbiter both are nouns.

Word	Noun	Adjective	Verb	Adverb
spacecraft	Yes	No	No	No
orbiter	Yes	No	No	No

As nouns, orbiter is a hypernym of spacecraft; that is, orbiter is a word with a broader meaning than spacecraft:

spacecraft: a craft capable of traveling in outer space; technically, a satellite around the sun
orbiter: man-made equipment that orbits around the earth or the moon

Other hypernyms of spacecraft include craft, artificial satellite, satellite.

spacecraft (noun)	orbiter (noun)
a craft capable of traveling in outer space; technically, a satellite around the sun	man-made equipment that orbits around the earth or the moon