tavern vs public house

tavern and public house both are nouns.

Word	Noun	Adjective	Verb	Adverb
tavern	Yes	No	No	No
public house	Yes	No	No	No

As nouns, public house is a hyponym of tavern; that is, public house is a word with a more specific, narrower meaning than tavern:

tavern: a building with a bar that is licensed to sell alcoholic drinks
public house: tavern consisting of a building with a bar and public rooms; often provides light meals

Other hyponyms of tavern include beer garden, bucket shop, gin mill, pothouse, pub, saloon, taphouse, rathskeller, shebeen.

tavern (noun)	public house (noun)
a building with a bar that is licensed to sell alcoholic drinks	tavern consisting of a building with a bar and public rooms; often provides light meals