quality vs high quality

quality and high quality both are nouns.

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

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

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

quality (noun)	high quality (noun)
an essential and distinguishing attribute of something or someone	the quality of being superior
(music) the distinctive property of a complex sound (a voice or noise or musical sound)
a degree or grade of excellence or worth
a characteristic property that defines the apparent individual nature of something
high social status

quality (adjective)	high quality (adjective)
of superior grade
of high social status