Law is a system of rules and regulations a society develops to settle disputes, enforce contracts, and protect property. It also includes the judicial system that interprets and applies these laws. Law can be a source of moral values and a guide to proper behaviour. It can also shape a culture, influence politics and economics, and mediate social change. Some laws can even define a nation.

In general, the purpose of law is to (1) keep the peace, (2) maintain the status quo, (3) preserve individual rights, (4) protect minorities against majorities, (5) promote social justice, and (6) provide for orderly social change. However, some legal systems serve these goals more effectively than others. For example, an authoritarian government may keep the peace but oppress its citizens and impose its will on society. Likewise, colonialism often brought peace but did not always respect local cultures or preserve minority rights.

There are two main types of law: civil and common. A civil law system is based on laws passed by the legislature or codified in constitutions and statutes. Its origins date back millennia. In modern times, the law is usually written in small books to make it easy for judges to understand and apply.

Civil law is the dominant form of law in most countries around the world. Common law systems, on the other hand, are based on judge-made precedent and are interpreted through case law. Judge-made law can be more flexible than a strict legislative code, but it can be more complicated to apply. Traditionally, these systems have not been as well-developed as civil law, but there are signs of convergence today.

The study of law is an important field of research and academic inquiry. Law is a complex and diverse subject, which can be divided into many different branches. For example, criminal law deals with crimes against the state or against individual people. Tort law covers damage to persons or their property, such as car accidents and defamation of character. It also covers the responsibility of businesses for harm caused by their activities.

Another branch of law is international law, which focuses on the relations between nations. This encompasses war, peace, and trade agreements. In the United States, laws are organized under a system of federal and state courts.

In addition to defining a nation, law can create a community of shared values, such as freedom, equality, and privacy. Law can also define a set of responsibilities that are required of all members of a society, such as the right to free speech and the obligation to obey the law. Finally, law can create a sense of fairness, such as the idea that everyone is equal before the court. These ideas are not universally accepted, and a number of scholars have criticized the way that Western culture and law treat certain groups of people. For example, indigenous peoples who have a different perception of law often disagree with Western concepts such as equality and the sanctity of life.