caliber vs high quality

caliber and high quality both are nouns.

Word	Noun	Adjective	Verb	Adverb
caliber	Yes	No	No	No
high quality	Yes	No	No	No

As nouns, high quality is a hyponym of caliber; that is, high quality is a word with a more specific, narrower meaning than caliber:

Other hyponyms of caliber include superiority, inferiority, low quality.

caliber (noun)	high quality (noun)
a degree or grade of excellence or worth	the quality of being superior
diameter of a tube or gun barrel