rings vs gymnastic apparatus

rings and gymnastic apparatus both are nouns.

Word	Noun	Adjective	Verb	Adverb
rings	Yes	No	No	No
gymnastic apparatus	Yes	No	No	No

As nouns, gymnastic apparatus is a hypernym of rings; that is, gymnastic apparatus is a word with a broader meaning than rings:

rings: gymnastic apparatus consisting of a pair of heavy metal circles (usually covered with leather) suspended by ropes; used for gymnastic exercises
gymnastic apparatus: sports equipment used in gymnastic exercises

Other hypernyms of rings include exerciser.

rings (noun)	gymnastic apparatus (noun)
gymnastic apparatus consisting of a pair of heavy metal circles (usually covered with leather) suspended by ropes; used for gymnastic exercises	sports equipment used in gymnastic exercises