A law is a set of rules decided by a particular place or authority meant for the purpose of keeping the peace and security of society. These laws are made by the government and can be enforced through various mechanisms created by the government itself whereby if they are breached, sanctions can be imposed.

Law is a vast field that covers a variety of subjects. For instance, criminal law deals with preventing people from breaking laws and dealing with those who do break them by finding guilt or innocence; family law covers legal relationships between members of the same household; maritime law deals with transporting goods and persons across international waters; administrative law involves how a government functions and how its decisions are made; and property law covers what happens when someone buys, sells, rents or gives away land and objects.

It is difficult to give a definitive definition of law as people have different ideas about what it means and how it should work. However, many books have been written on the subject and the prevailing ideas are that a nation needs laws to ensure that everyone can live peacefully and that any disputes between people can be resolved. It is also the case that a nation must ensure that core human, procedural and property rights are protected.

The creation of a law is influenced by how a government is structured and what its constitution enshrines. Some countries have a supreme court which can remove laws that violate a constitution; others have a judicial system with an appeals process for citizens to get their law challenges heard.

Modern laws have been shaped by a range of factors including political ideology, economic trends and social change. For example, some countries use their law to keep the peace and maintain status quo; other nations use it to promote social justice and provide a framework for orderly social change.

Laws are usually enacted by governments and interpreted by the courts. The judiciary is a group of judges who decide whether or not a person guilty of a crime is guilty; they also rule on cases involving civil rights and freedoms.

A lawyer is a person who practices law; this includes researching and writing about laws and representing clients in court. A lawyer must meet certain professional standards and must be recognised as a qualified lawyer by a regulating body, such as a bar association or a law society. Lawyers can achieve a distinct professional identity by passing a qualifying examination and/or having a specific qualification (such as a Bachelor of Laws, a Master of Laws or a Juris Doctor degree). Most jurisdictions have separate laws that deal with the practice of law, the qualifications required to be a solicitor or barrister and the training that is necessary before they can become admitted to the legal profession. Law is a complex and essential aspect of modern society. It has a profound effect on politics, economics and history.