indoor garden vs glasshouse

indoor garden and glasshouse both are nouns.

Word	Noun	Adjective	Verb	Adverb
indoor garden	Yes	No	No	No
glasshouse	Yes	No	No	No

As nouns, glasshouse is a hypernym of indoor garden; that is, glasshouse is a word with a broader meaning than indoor garden:

indoor garden: a greenhouse in which plants are arranged in a pleasing manner
glasshouse: a building with glass walls and roof; for the cultivation and exhibition of plants under controlled conditions

Other hypernyms of indoor garden include greenhouse.

indoor garden (noun)	glasshouse (noun)
a greenhouse in which plants are arranged in a pleasing manner	a building with glass walls and roof; for the cultivation and exhibition of plants under controlled conditions