In science, the word law refers to a statement that describes regular or patterned relationships among observable phenomena (see physical law). Laws of mathematics and logic describe the nature of rational thought and inference. Laws of economics describe the nature of human behavior and interaction. Many adages are popularly called "laws".
In politics, and jurisprudence, the word "law" refers to a statement that prescribes or proscribes specified relationships among people. This article focuses on this sort of law.
Law as legal term
According to Western liberal political theory, a body of law attempts to balance individual rights and social control, which are viewed as being inversely related, and is enforced by a system of criminal justice. Many social scientists use the term more broadly, to refer both to formal and informal systems of social control. In most political and legal theory, however, it refers specifically to a formal system administered and enforced by a government, and more generally to include all aspects of governmental decision making and maintenance of social order.
Branches of law
Law stems from customs of a people that achieve enough acceptance to become the expected and enforced norm. The process of acceptance is accelerated by the existence of legislative bodies who deliverately seek to craft and impose norms of behavior as if they were or should be customs.
Law includes the processes of enacting statutes and regulations, and the resolution of disputes between individual persons or companies or the government.
Civil law generally seeks to enforce the rights created by the various statutes by allowing the party whose rights have been violated to collect money (damages) from the party who violated those rights. Where money damages are insufficient to protect someone's legal rights, the court may offer other remedies such as forbiding someone to do an act (an injunction, for example) under pain of contempt or formally changing someone's legal status (divorce, for example).
Criminal law, by contrast, is the system of laws that explain antisocial acts that are punishable by governmental sanctions such as imprisonment and/or fine. The state has primary responsibility for enforcing the criminal laws to protect its citizens.
Legal system
Different parts of the world have different legal systems.
The system of Common law is derived from Anglo-Saxon customary law. It is used in England, the United States and other former British possessions such as India, Canada, Australia, and Ireland.
The alternative to common law, within the Western legal tradition, is Civil law proper. It refers to a system of statutory law and is usually subdivided into French, German and Scandinavian Civil law. Especially French and German Civil law have their roots in ancient Roman law but Civil law also has Germanic influences. A pathbreaking achievement was the French Napoleonic Code which heavily influenced also the German tradition. Civil law is used in most of Europe and former European colonies (other than British), including Latin America.
Civil law and Common law differ more markedly in procedure and terminology, than in their substantive content.
In states of the former Soviet Union and its satellites and other communist countries such as Vietnam, North Korea, China and Cuba a system of socialist law based on the civil law tradition was developed. With the end of the cold war, most of these nations are incorporating substantive rules and procedures compatible with private property and the conduct of business into their legal systems.
In Arab and other Islamic countries such as Saudi Arabia and Iran traditional Islamic Law derived from the Koran may be in use.
Law as academic discipline and profession
In addition to being part of the societal framework law is also an academic discipline and a profession. Lawyers are sometimes called by other names, as in England where the profession is divided between solicitors and barristers. They are professionally trained in the United States at postgraduate schools of law. Many persons who attend law school never practice law but use their knowledge of law in another profession. See Law (academic) and jurisprudence For law as a profession, see lawyer and practice of law.
Further Discussion
Most laws and legal systems --at least in the Western world-- are quite similar in their essential themes, arising from similar values and similar social, economic, and political conditions, and they typically differ less in their substantive content than in their jargon and procedures. One of the fundamental similarities across different legal systems is that, to be of general approval and observation, a law has to appear to be public, effective, and legitimate, in the sense that it has to be available to the knowledge of the citizen in common places or means, it needs to contain instruments to grant its application, and it has to be issued under given formal procedures from a recognized authority. In the context of most legal systems, laws are enacted through the processes of constitutional charter, constitutional amendment, legislation, executive order, rulemaking, and adjudication; within Common law jurisdictions, rulings by judges are an important additional source of legal rules. However, de facto laws also come into existence through custom and tradition.
A particular society or community adopts a specific set of laws to regulate the behavior of its own members, to order life in its political territory, to grant or acknowledge the rights and privileges of its citizens and other people who may come under the jurisdiction of its courts, and to resolve disputes. There are several distinct laws and legal traditions, and each jurisdiction has its own set of laws and its own legal system. Individually codified laws are known as statutes, and the collective body of laws relating to one subject or emanating from one source are usually identified by specific reference. (E.g., Roman law, Common law, and Criminal law.) Moreover, the several different levels of government each produce their own laws, though the extent to which law is centralized varies. Thus, at any one place there can be conflicting laws in force at the local, regional, state, national, or international levels.

