Law is an orderly set of rules that governs social behavior and is enforced by the government. A person who does not follow the law can be fined or jailed.
The laws of a nation serve a variety of purposes, including to keep the peace, maintain the status quo, preserve individual rights, protect minorities against majorities, promote social justice, and provide for orderly social change. Some legal systems are more effective than others at doing these things.
There are three main types of law: criminal, civil, and administrative. In most nations, criminal law focuses on crimes that are considered against the interests of the society (e.g., murder) and can be punished by imprisonment or fines.
Commercial law covers a variety of areas, such as contracts, property, sales and insurance. Some of the most important fields in commercial law are company law, which traces back to the English restraint of trade doctrine; and international law, which is used to regulate business and trade between countries.
In common law, court decisions are recognized as valid law on equal footing with statutes adopted by legislative bodies or regulations issued by the executive branch. This is a feature known as stare decisis.
Unlike other sciences, law is prescriptive rather than descriptive or causal. Moreover, claims, privileges, powers and immunities are regarded as normative statements that determine what parties may or may not do (claims, privileges and powers) or cannot do (immunities). This makes it difficult to compare law with other disciplines.