playroom vs recreation room

playroom and recreation room both are nouns.

Word	Noun	Adjective	Verb	Adverb
playroom	Yes	No	No	No
recreation room	Yes	No	No	No

As nouns, recreation room is a hypernym of playroom; that is, recreation room is a word with a broader meaning than playroom:

playroom: a recreation room for noisy activities (parties or children's play etc)
recreation room: a room equipped for informal entertaining

Other hypernyms of playroom include rec room.

playroom (noun)	recreation room (noun)
a recreation room for noisy activities (parties or children's play etc)	a room equipped for informal entertaining