Law is a set of rules enforceable by social institutions. They include the courts, the executive, and civil society. These institutions are primarily responsible for providing justice.

Legal systems can be divided into three broad categories: common law, civil law, and religious law. All of these systems have common features, but they differ in some aspects.

In a common law system, decisions are made by a judge in a case, and the decision is called a “case law” or a “precedent.” This means that a future court will be bound by the decision. The doctrine of precedent is important because it means that the same judge’s decision will bind the future decisions of the same court.

Unlike the common law system, a civil law system does not rely on a judge’s personal interpretation of the case. The only writing that a judge does in a civil law system is to decide one case.

The difference between common law and civil law systems is that the former requires less human elaboration and involves less detailed judicial decisions. These systems are used in many countries.

The concept of a “natural law” arose in the ancient Greek philosophy and in connection with the notion of justice. These concepts have entered mainstream culture through the writings of Thomas Aquinas.

The concept of religious law is based on religious precepts. These are specifically used by the Catholic Church and Eastern Orthodox Church. Canon law is also used in some church communities.