guidance system vs guidance device

guidance system and guidance device both are nouns.

Word	Noun	Adjective	Verb	Adverb
guidance system	Yes	No	No	No
guidance device	Yes	No	No	No

As nouns, guidance system and guidance device are synonyms defined as:

guidance system and guidance device: a system of equipment for automatically guiding the path of a vehicle (especially a missile)

guidance system (noun)	guidance device (noun)
a system of equipment for automatically guiding the path of a vehicle (especially a missile)	a system of equipment for automatically guiding the path of a vehicle (especially a missile)