Law is a system of rules that societies or governments develop in order to regulate behavior, deal with crime and arrange business agreements. It is also a subject of study that informs politics, economics, history and social relationships. The precise nature of law is a source of debate and controversy, and it provides a topic for scholarly inquiry into legal history, philosophy, ethics, political science and sociology.
Legal systems vary from country to country, and even within a single nation, but they do tend to group together into broad categories based on historically accepted justice ideals. The major groups include civil law, common law and religious law. Civil laws rely on concepts, categories and rules that are based on Roman law or the Germanic law of the Anglo-Saxon kingdoms, while common law systems rely on judge-made precedent and the doctrine of stare decisis. Religious laws primarily derive from the scriptures of a particular religion, including Jewish halakha and Islamic Sharia.
While laws may cover a wide range of topics, they typically fall into three broad categories: civil law; criminal law and constitutional law. Criminal law deals with the punishment of those who commit offenses against society, such as murder or fraud. Civil law addresses disputes between private parties, such as property disputes or wrongful termination of employment. Constitutional law is a branch of public law that deals with fundamental rights and freedoms, such as the right to vote or to freely assemble.
A more detailed look at the fields of law can be found by examining specific branches of it. Air law, for example, involves regulations governing travel and trade by airplane. Labor law examines the tripartite industrial relationship between worker, employer and trade union, while property law focuses on ownership of land and buildings. Laws that govern medical jurisprudence are an important part of the field of law, as are those that deal with taxation and banking.
Another field of law is space law, which addresses the legal aspects of human activities in Earth orbit and outer space. The field of law also includes commercial laws that regulate the conduct of businesses in areas such as merchandising and marketing, or intellectual property laws that protect inventions from being copied by others.
The concept of law is a complex and evolving one that influences politics, economics and history in many ways. It is also a significant source of conflict and dispute, and it raises issues of equality and fairness. The way that people experience the law differs as well, with rich and poor people often having very different experiences of what constitutes justice. This difference is reflected in the narratives that rich and poor individuals tell themselves about the law, and which are sometimes enshrined in codified community narratives of equal justice for all. In addition, the speed at which the law moves varies as well, with some countries moving faster than others. The speed at which the law moves is therefore something that a citizen can never know in advance.