A law is a set of rules that a society or country has enacted to govern its affairs. People are obligated to follow these laws, and breaking them can lead to jail time or fines. A law can be an individual set of rules, or it can refer to all the laws in a country or area. For instance, if murder is against the law, it means that a person may not commit the crime in that geographic area.

Law is a branch of science that touches virtually every aspect of society. The three main branches of law are civil law, criminal law, and economic law. Each focuses on a different aspect of society. There is also labour law, which involves the tripartite industrial relationship between employees and employers and the regulation of collective bargaining and the right to strike. Other fields are civil procedure and evidence law, which deal with the rules of court proceedings.

For the rule of law to work, laws must be accessible and understandable to the general public. Many areas of law are very technical and difficult to understand for laypersons. This means that the layperson will usually need the services of a lawyer or another professional to be fully aware of their rights.