reference frame vs coordinate system

reference frame and coordinate system both are nouns.

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

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

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

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

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