practice of medicine vs medical specialty

practice of medicine and medical specialty both are nouns.

Word	Noun	Adjective	Verb	Adverb
practice of medicine	Yes	No	No	No
medical specialty	Yes	No	No	No

practice of medicine (noun)	medical specialty (noun)
the learned profession that is mastered by graduate training in a medical school and that is devoted to preventing or alleviating or curing diseases and injuries	the branches of medical science that deal with nonsurgical techniques