bearing vs ball bearing

bearing and ball bearing both are nouns.

Word	Noun	Adjective	Verb	Adverb
bearing	Yes	Yes	No	No
ball bearing	Yes	No	No	No

As nouns, ball bearing is a hyponym of bearing; that is, ball bearing is a word with a more specific, narrower meaning than bearing:

bearing: a rotating support placed between moving parts to allow them to move easily
ball bearing: bearings containing small metal balls

Other hyponyms of bearing include needle bearing, roller bearing, fifth wheel, journal bearing, thrust bearing.

bearing (noun)	ball bearing (noun)
a rotating support placed between moving parts to allow them to move easily	bearings containing small metal balls
heraldry consisting of a design or image depicted on a shield
dignified manner or conduct
characteristic way of bearing one's body
the direction or path along which something moves or along which it lies
relevant relation or interconnection

bearing (adjective)	ball bearing (adjective)
(of a structural member) withstanding a weight or strain