reference frame vs reference system

reference frame and reference system both are nouns.

Word	Noun	Adjective	Verb	Adverb
reference frame	Yes	No	No	No
reference system	Yes	No	No	No

As nouns, reference frame and reference system are synonyms defined as:

reference frame and reference system: a system that uses coordinates to establish position

Other synonyms of reference frame include coordinate system, frame of reference.

reference frame (noun)	reference system (noun)
a system that uses coordinates to establish position	a system that uses coordinates to establish position