Law is the set of enforceable rules created and enforced by social or governmental institutions to regulate behavior. Laws are the foundation for a civilized society, ensuring that everyone gets along peacefully by resolving disputes through the courts or other appropriate channels. Laws also ensure that people are treated fairly, and protect their personal and property rights. In the modern world, laws may be federal, state, or local, and they can be based on religious beliefs, racial, cultural, or ethnic groups, or simply on common sense and fairness.

Laws may be made by a legislative process, resulting in statutes, or they can be established by judges through precedent, as in the case of common law jurisdictions. Private individuals may also create legally binding contracts and other legal documents that establish their own rules of conduct. Laws are complex from a methodological point of view, because they contain normative statements (i.e., “ought to”) that are not easily compared to descriptive or causal statements in empirical science (such as the law of gravity) or even in social science (such as the “law of demand and supply” in economics).

Because the concept of what constitutes law is so contested, laws vary considerably from one nation to the next. Political and economic circumstances shape the scope and nature of law, and there is a constant tension between the needs of the economy and the demands of justice. Moreover, the nature of the relationship between law and the social system is constantly changing: revolutions occur, aspirations for democracy are voiced, and new challenges to existing social-legal authority arise.

There are countless branches of law, which can be broadly categorized as civil or criminal, and which address such issues as torts, contracts, family, property, and intellectual property. In addition, there is a body of law that deals with the relations between states and the international arena.

The practice of law is a highly specialized field and requires training in both jurisprudence and the practical application of legal knowledge. Lawyers are usually required to follow strict professional procedures in order to maintain their status as a licensed member of the profession.

The study of law is fascinating because it reveals the many ways that societies organize themselves through social-legal institutions. The law shapes politics, economics, history, and culture in a variety of ways. The law can be a source of confusion because it is frequently amended, repealed, and replaced with new laws. This is especially true of the United States, where there are federal and state laws, as well as regulations by governing agencies. In addition, laws can be complicated by the fact that different jurisdictions have their own unique law-making processes. A complex web of conflicting and overlapping laws can be found in the United States, making it difficult for a citizen to understand his or her rights.