Law is a system of rules governing conduct, including those that affect the rights and privileges of individuals and communities. Laws are enforceable through courts, which make decisions and impose sanctions, and through other institutions, such as a police force. The study of law includes the practice, history and philosophy of legal systems.
Legal systems vary in their organization, scope and power. A legal system aims to achieve several objectives: the establishment of standards, maintaining order, resolving disputes, and protecting liberties and property. Some systems may achieve these objectives more effectively than others.
The fundamental principles of a legal system include supremacy of the law, equality before the law, accountability to the law, separation of powers, participation in decision making and avoidance of arbitrariness. These principles apply to the public and private sectors alike, including the state itself.
There are three main categories of law, though these subjects often intertwine: civil, criminal and administrative. Civil law deals with the relationships between people, such as contracts and ownership of property; it covers such areas as marriage, divorce and inheritance. Criminal law concerns violations of public order and the protection of individuals against harm caused by others, such as robbery or murder. Administrative law encompasses the legal relationship between government and private enterprise, such as regulations governing energy, water and telecommunications.
A person who practises law is a lawyer, barrister or solicitor. Other legal professionals include paralegals, trainee solicitors and secretaries. The legal profession is a highly respected one, and there are many well-known personalities who have achieved fame as lawyers or judges.
In countries with a common law legal system, judicial decisions are acknowledged as law on an equal footing with statutes passed through legislative process and regulations issued by the executive branch. This is known as the doctrine of stare decisis (Latin for “to stand by decisions”). In contrast, a civil law system generally bases its laws on a set of codes compiled from earlier case law, and judges follow precedent when reaching their decisions.
Countries that do not have strong formal justice systems can rely on customary law, which is based on local traditions that shape ideas of justice. Some of these traditions are universal, such as the need for fair treatment and respect for people, but most are unique to a particular culture.
Laws can regulate the activities of private and public enterprises, such as utilities and telecommunications, or they can punish offences against the state, such as theft or defamation. Some laws are designed to encourage social good, such as the ban on advertising tobacco products or the requirement that people wear seatbelts in cars. Others, such as the prohibition on aggressive telemarketing or the ban on playing loud music late at night, are designed to protect individual liberty and property.