Law is a set of rules that help to keep order, protect property and keep people safe. It sets out standards and imposes consequences for breaking them, which can range from fines to jail time. Laws are created and established by the government and apply to everyone equally. Laws can be created through statutes (passed by the legislature), ordinances, common law or judicial decisions. Laws can also be based on religious precepts, such as Jewish Halakhah and Islamic Shari’ah or Christian canon law. The study of laws and legal systems is called jurisprudence.

The law can be broken through civil or criminal action, but the core function is restraining those in power from using their authority to harm others. The nature of the political-legal system and the resulting law will vary from nation to nation, but in all cases it is necessary to understand who makes the laws and how they are enforced.

For example, a person may commit a crime by defrauding another or by stealing something of value from them. If this is proved in court, the guilty party can be imprisoned and made to pay compensation. Likewise, a person who does something which harms the environment is subject to criminal prosecution by environmental officers and must pay for any damages.

In addition to criminal and environmental law, there are many other areas of law which cover important parts of life. These include contract law (which regulates agreements to exchange goods and services), property law (which defines people’s rights and duties toward tangible property such as houses or cars) and intellectual property law (which covers copyrights, trademarks and patents).

Laws also govern a wide range of other issues of social justice. Labour law covers workers’ rights and conditions, welfare law deals with the provision of public services such as water and electricity, and family law encompasses divorce proceedings and the rights of children. In addition, immigration and nationality law deal with the right to live in a nation-state of choice and to acquire or lose citizenship.

The term law is also used to refer to the overall process of a case and its resolution, including procedural law, evidence law and bankruptcy law. Procedural law also includes how a trial is conducted, with the use of jury selection and voir dire, and how evidence is presented in court. Evidence law is the collection and evaluation of all evidence in a case, including circumstantial and testimonial evidence. A judge decides a case on the basis of this evidence, with any decision being backed up by precedent (a prior court ruling in a similar situation). This is a key principle of the American civil litigation system. A lawsuit is initiated by filing a complaint, or pleading, in a court. The court records all activities in a lawsuit in a book called the case record. A person who is unable to afford an attorney can present their case in court with the assistance of a lawyer called a public defender.