handbag vs shoulder bag

handbag and shoulder bag both are nouns.

Word	Noun	Adjective	Verb	Adverb
handbag	Yes	No	No	No
shoulder bag	Yes	No	No	No

As nouns, shoulder bag is a hyponym of handbag; that is, shoulder bag is a word with a more specific, narrower meaning than handbag:

handbag: a container used for carrying money and small personal items or accessories (especially by women)
shoulder bag: a large handbag that can be carried by a strap looped over the shoulder

Other hyponyms of handbag include clutch, clutch bag, etui, evening bag, reticule.

handbag (noun)	shoulder bag (noun)
a container used for carrying money and small personal items or accessories (especially by women)	a large handbag that can be carried by a strap looped over the shoulder