inertial navigation system vs inertial guidance system

inertial navigation system and inertial guidance system both are nouns.

Word	Noun	Adjective	Verb	Adverb
inertial navigation system	Yes	No	No	No
inertial guidance system	Yes	No	No	No

As nouns, inertial navigation system and inertial guidance system are synonyms defined as:

inertial navigation system and inertial guidance system: a system to control a plane or spacecraft; uses inertial forces

inertial navigation system (noun)	inertial guidance system (noun)
a system to control a plane or spacecraft; uses inertial forces	a system to control a plane or spacecraft; uses inertial forces