duty vs role

duty and role both are nouns.

Word	Noun	Adjective	Verb	Adverb
duty	Yes	No	No	No
role	Yes	No	No	No

As nouns, role is a hyponym of duty; that is, role is a word with a more specific, narrower meaning than duty:

duty: work that you are obliged to perform for moral or legal reasons
role: the actions and activities assigned to or required or expected of a person or group

Other hyponyms of duty include chore, job, task, function, office, part, assignment, duty assignment.

duty (noun)	role (noun)
the social force that binds you to the courses of action demanded by that force	the actions and activities assigned to or required or expected of a person or group
work that you are obliged to perform for moral or legal reasons	normal or customary activity of a person in a particular social setting
a government tax on imports or exports	what something is used for
	an actor's portrayal of someone in a play