shoulder bag vs handbag

shoulder bag and handbag both are nouns.

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

As nouns, handbag is a hypernym of shoulder bag; that is, handbag is a word with a broader meaning than shoulder bag:

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

Other hypernyms of shoulder bag include bag, pocketbook, purse.

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