prescriptive grammar vs grammar

prescriptive grammar and grammar both are nouns.

Word	Noun	Adjective	Verb	Adverb
prescriptive grammar	Yes	No	No	No
grammar	Yes	No	No	No

As nouns, grammar is a hypernym of prescriptive grammar; that is, grammar is a word with a broader meaning than prescriptive grammar:

prescriptive grammar: a grammar that is produced by prescriptive linguistics
grammar: the branch of linguistics that deals with syntax and morphology (and sometimes also deals with semantics)

prescriptive grammar (noun)	grammar (noun)
a grammar that is produced by prescriptive linguistics	the branch of linguistics that deals with syntax and morphology (and sometimes also deals with semantics)