Law is a system of rules enforced by governmental or societal institutions to regulate behavior, yet its precise definition remains a longstanding debate—described variously as a science, the art of justice, or even simply predictions of court decisions. Legal systems vary by jurisdiction, with civil law countries codifying laws through legislatures, common law systems relying on binding judge-made precedent, and religious law influencing some states. The scope of law divides into public law (governing government and society, such as constitutional and criminal law) and private law (resolving disputes between parties, like contracts and torts), a distinction that is stronger in civil law nations. Jurisprudence, the philosophy of law, asks what law is and should be, with notable thinkers like H.L.A. Hart (a system of rules), John Austin (sovereign commands backed by sanctions), and Ronald Dworkin (an interpretive concept for justice) offering contrasting perspectives. The term "law" derives from Old Norse lǫg, and the field deeply shapes politics, economics, and history while raising profound questions about equality, fairness, and justice.