bedsitter vs apartment

bedsitter and apartment both are nouns.

Word	Noun	Adjective	Verb	Adverb
bedsitter	Yes	No	No	No
apartment	Yes	No	No	No

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

bedsitter: 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 bedsitter include flat.

bedsitter (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