Obligation: an act or course of action to which a party (natural or legal person) is morally or legally bound. An obligation is a duty by which a person is bound or obliged to carry out certain action, or desist/refrain from certain action, and which arises out of a sense of duty or results from custom, morality, rules or law. An obligation is a form of commitment that is not voluntary in nature, and subjects the obliged party (duty holder) to consequences or penalties for its nonfulfillment.

In law, an obligation is a form of contract or agreement enforceable by law, a document embodying such an agreement, or a bond containing a penalty, with a condition annexed for payment of money, performance of covenants, or other form of remedy. In international law, an obligation may take the form of a “treaty,” “covenant,” “convention,” “peremptory norm” (of customary law) or other instrument of binding law (hard law, or lex lata). An obligation imposes an explicitly binding condition on the duty holder subject to monitoring, review and/or enforcement by a body, mechanism or tribunal legally authorized for the purpose of determining and enforcing penalty for the committing party in the event of its failure to fulfill the commitment. Not all treaty-monitoring bodies are authorized with the power to enforce consequences, penalties and remedies directly. However, in the case of gross or systematic violations, the breach may be subject to further decisions or resolutions taken in political bodies to refer the duty holder to a tribunal with enforcement capacity.