Moral duty refers to the responsibilities individuals have to act in ways that are considered right or ethical. It is often guided by personal beliefs, societal norms, and cultural values. People may feel a moral obligation to help others, tell the truth, or uphold justice, which can vary from one community to another. This concept is closely related to ethics, which is the study of what is right and wrong. Philosophers like Immanuel Kant have emphasized the importance of moral duty, suggesting that individuals should act according to principles that could be universally applied.