'义务' (yìwù) is a noun meaning 'duty' or 'obligation'—a moral, legal, or social responsibility that one is expected to fulfill. The first character 义 (yì) means 'righteousness', 'justice', or 'moral principle', while 务 (wù) means 'task', 'affair', or 'matter'. Together, they convey the idea of a morally or socially required task—not something optional, but something one *ought* to do based on role, law, or shared values.

This word appears frequently in formal and semi-formal contexts: civic life (e.g., tax payment, military service), family roles (e.g., caring for aging parents), professional ethics, and education. It carries a sense of seriousness and expectation, often implying consequences if neglected. Unlike the more personal or emotional term 责任 (zérèn, 'responsibility'), 义务 emphasizes duty rooted in external standards—laws, customs, or institutional norms—and is commonly used in official documents, news reports, and public discourse.