buffer solution vs PBS

buffer solution and PBS both are nouns.

Word	Noun	Adjective	Verb	Adverb
buffer solution	Yes	No	No	No
PBS	Yes	No	No	No

As nouns, PBS is a hyponym of buffer solution; that is, PBS is a word with a more specific, narrower meaning than buffer solution:

Other hyponyms of buffer solution include starting buffer, phosphate buffer solution, bicarbonate buffer solution.

buffer solution (noun)	PBS (noun)
a solution containing a buffer	a solution containing a phosphate buffer