schoolroom vs homeroom

schoolroom and homeroom both are nouns.

Word	Noun	Adjective	Verb	Adverb
schoolroom	Yes	No	No	No
homeroom	Yes	No	No	No

As nouns, homeroom is a hyponym of schoolroom; that is, homeroom is a word with a more specific, narrower meaning than schoolroom:

schoolroom: a room in a school where lessons take place
homeroom: a classroom in which all students in a particular grade (or in a division of a grade) meet at certain times under the supervision of a teacher who takes attendance and does other administrative business

Other hyponyms of schoolroom include home room, lecture room, study hall.

schoolroom (noun)	homeroom (noun)
a room in a school where lessons take place	a classroom in which all students in a particular grade (or in a division of a grade) meet at certain times under the supervision of a teacher who takes attendance and does other administrative business