Law is the set of rules and sanctions that a community recognises as binding on its members. Its main functions are to order and govern, and to protect citizens from physical harm and exploitation. It also shapes politics, economics, history and society in many ways. The concept of law has a wide and deep significance, which is reflected in the great variety of legal systems around the world. Its foundations are the principles of natural justice, which are recognised and respected internationally as part of human rights. Its disciplinary aspects include the study of legal philosophy and practice.
The most basic definition of law is a set of commands issued by the state, and sanctioned by penalties on those who do not obey. But the range of laws extends far beyond the practical and enforceable ones, with morality often playing a central role. Whether the defining features of law are commandments, regulations or guidelines is a matter of debate.
Throughout history, people have sought to create law through various means. In modern times, revolutionary ideas like Max Weber reshaped thinking on the extension of state power and its need for accountability. The aspiration to create a democratic system that gives each citizen greater rights is a theme in many constitutions, and political systems are usually structured around a mix of legislative, executive and judicial power.
Many laws are made at the local or regional level. At the federal level, the Constitution gives Congress limited powers to enact statutes, which are codified in the United States Code. Federal agencies may also make regulations, which – if they are published in the Federal Register and compiled into the Code of Federal Regulations – carry the force of law. Judicial decisions on the meaning of such regulations are binding on lower courts under the doctrine of stare decisis.
Other laws are made at the national or international level. Immigration law and nationality law concern the right of people to live in a nation-state that is not their own, to acquire and lose citizenship, and the status of stateless persons. Employment law concerns the tripartite industrial relationship between worker, employer and trade union, and includes laws on health and safety at work and collective bargaining. Property law covers the ownership of land, buildings and goods. Criminal law lays down punishments for crimes, and evidence law considers which materials are admissible in court cases.
Most legal systems incorporate traditions that have religious roots. In these, religious law – based on the Jewish Halakhah and Islamic Shariah, or Christian canon law – is a source of law through interpretation, Qiyas (reasoning by analogy), Ijma (consensus) and precedent. In addition, some religious legal systems rely on further elaboration to provide thorough and detailed law. This elaboration takes the form of the Talmud and Midrash. Other traditional legal systems are rooted in Chinese law, European law and Indian law. Legal theory and practice explore the origins, development and societal impacts of law.