Sheetrock vs plasterboard

Sheetrock and plasterboard both are nouns.

Word	Noun	Adjective	Verb	Adverb
Sheetrock	Yes	No	No	No
plasterboard	Yes	No	No	No

As nouns, plasterboard is a hypernym of Sheetrock; that is, plasterboard is a word with a broader meaning than Sheetrock:

Sheetrock: a kind of plasterboard
plasterboard: wallboard with a gypsum plaster core bonded to layers of paper or fiberboard; used instead of plaster or wallboard to make interior walls

Other hypernyms of Sheetrock include gypsum board.

Sheetrock (noun)	plasterboard (noun)
a kind of plasterboard	wallboard with a gypsum plaster core bonded to layers of paper or fiberboard; used instead of plaster or wallboard to make interior walls