Law is a system of rules and regulations created by a country or community that governs its people and activities. It defines what people can and cannot do, regulates business and social relationships, protects property rights, punishes criminals, and provides a framework for a peaceful society. The study of law covers a broad range of topics, from international relations and constitutional theory to criminal justice, family law and property law. It also encompasses the history and philosophy of legal systems, legal education and the legal profession.

Many books containing different ideas and definitions of law have been written, but the central theme is that laws create a set of rules to ensure a peaceful society. These are enforced by mechanisms and, if they are broken, sanctions can be imposed.

In common law legal systems, decisions by courts are explicitly acknowledged as “law” on equal footing with legislative statutes and executive regulations. The principle of “stare decisis” means that decisions made by higher courts bind lower courts to assure that similar cases reach similar results. By contrast, in civil law systems legislative statutes are often more detailed and judicial decisions shorter and less comprehensive.

A core element of the law is that it enables people to seek compensation (repayment) from others who have damaged their property or health. Other goals include promoting fairness, public safety and economic stability. In the modern era, law is increasingly intertwined with issues of globalization and terrorism.

The law has evolved over a long time. It contains elements that are very old, such as the coroners’ courts with a 800-year history, and elements that are very modern, such as judges using laptop computers to decide cases. The legal system is complex and has been successfully adapted to a wide variety of social settings, disputes over government and the nature of human society.

For example, in an age of genetic engineering and biotechnology, legal systems need to be able to deal with issues such as the ownership of living organisms. Laws also need to be developed to ensure that people receive equal treatment, regardless of race or social class.

The complexity of the law means that there are a lot of sub-disciplines, each focusing on a particular area of the law. For example, immigration law deals with the rights of foreigners to live and work in a nation-state that is not their own. Employment law involves the tripartite industrial relationship of worker, employer and trade union, whereas contract law deals with the terms of commercial transactions. Evidence law focuses on which materials are admissible in court and which are not.