Law is a system of rules, enforceable by the government of a country or region, that governs how people can live together. It includes a number of different types of rules, such as those that determine property rights, the duties and responsibilities of citizens, and the punishment for breaking laws. Laws can be enacted by governments or private individuals. They may be enforced by police, courts or punishments like fines and jail. There are also a number of fields that study how laws work.

The most well-known field is the law of property, which defines how people can own and use tangible things such as land and buildings or movable items like cars and furniture. Other fields include criminal and civil law, which address disputes between people or between people and the government. These kinds of fields are important because they provide guidelines for how people should behave and prevent people from harming others or themselves.

A broader view of law includes the idea that all societies are governed by rules that regulate how people should live and what they can do. The precise nature of these rules is the subject of ongoing debate. In most modern societies, laws are enacted by groups of politicians in a legislature such as a parliament or congress who are elected (chosen) by the governing peoples. Those laws are then put into a constitution which sets out the overall framework of society and guides how further laws can be made.

In addition to these general laws, most countries have a system of courts to resolve individual cases. These courts, based on constitutional principles, are either called the judiciary or the justice system. Judges decide which laws to uphold or reject based on evidence and how they should be interpreted. They may also be guided by the principle of stare decisis, which holds that a decision made by one judge should bind other judges on how to rule in similar cases.

Many people have jobs that deal with law. These jobs include lawyers, who are trained in the law and help people fight court cases, and prosecutors who prosecute criminals. Other jobs in the law deal with interpreting legal documents, advising clients about their rights, and representing people before a judge or jury. Lastly, there are fields of study that focus on the way that laws work, including constitutional law and the philosophy of law.