caramel bun vs sweet roll

caramel bun and sweet roll both are nouns.

Word	Noun	Adjective	Verb	Adverb
caramel bun	Yes	No	No	No
sweet roll	Yes	No	No	No

As nouns, sweet roll is a hypernym of caramel bun; that is, sweet roll is a word with a broader meaning than caramel bun:

caramel bun: rolled dough spread with sugar and nuts then sliced and baked in muffin tins with honey or sugar and butter in the bottom
sweet roll: any of numerous yeast-raised sweet rolls with our without raisins or nuts or spices or a glaze

Other hypernyms of caramel bun include coffee roll.

caramel bun (noun)	sweet roll (noun)
rolled dough spread with sugar and nuts then sliced and baked in muffin tins with honey or sugar and butter in the bottom	any of numerous yeast-raised sweet rolls with our without raisins or nuts or spices or a glaze