gulag vs prison camp

gulag and prison camp both are nouns.

Word	Noun	Adjective	Verb	Adverb
gulag	Yes	No	No	No
prison camp	Yes	No	No	No

As nouns, prison camp is a hypernym of gulag; that is, prison camp is a word with a broader meaning than gulag:

Other hypernyms of gulag include internment camp, POW camp, prisoner of war camp.

gulag (noun)	prison camp (noun)
a Russian prison camp for political prisoners	a camp for trustworthy prisoners employed in government projects
	a camp for prisoners of war