bedsitting room vs apartment

bedsitting room and apartment both are nouns.

Word	Noun	Adjective	Verb	Adverb
bedsitting room	Yes	No	No	No
apartment	Yes	No	No	No

As nouns, apartment is a hypernym of bedsitting room; that is, apartment is a word with a broader meaning than bedsitting room:

bedsitting room: a furnished sitting room with sleeping accommodations (and some plumbing)
apartment: a suite of rooms usually on one floor of an apartment house

Other hypernyms of bedsitting room include flat.

bedsitting room (noun)	apartment (noun)
a furnished sitting room with sleeping accommodations (and some plumbing)	a suite of rooms usually on one floor of an apartment house