Duty
Part of speech: noun
Definition: That which one is morally or legally obligated to do. A period of time spent at work or doing a particular task. describing a workload as to its idle, working and de-energized periods. A tax placed on imports or exports; a tariff. One's due, something one is owed; a debt or fee.
Obligation
Part of speech: noun
Definition: The act of binding oneself by a social, legal, or moral tie to someone.A social, legal, or moral requirement, duty, contract, or promise that compels someone to follow or avoid a particular course of action.A course of action imposed by society, law, or conscience by which someone is bound or restricted.A legal agreement stipulating a specified payment or action; the document containing such agreement.