guidance device vs guidance system

guidance device and guidance system both are nouns.

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

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

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

guidance device (noun)	guidance system (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)