gulag vs internment camp

gulag and internment camp both are nouns.

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

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

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

gulag (noun)	internment camp (noun)
a Russian prison camp for political prisoners	a camp for prisoners of war