Law is the set of rules a society or government develops to deal with such issues as crime, business agreements, and social relationships. It is also a field of study that encompasses legal history, philosophy, economic analysis and sociology. People involved in the practice of law may be known as lawyers or attorneys-at-law. Lawyers who specialize in criminal law are called prosecutors and those who specialize in civil law are called defense lawyers.

Law governs people’s daily lives in many ways and is a source of controversy and debate. For example, some people think that obscene phone calls are against the law, while others believe that it is not. Some laws are very specific, such as those governing airplanes, while others are broad in scope, such as those governing contracts or property. Laws are a vital part of any modern society and they can be enforced by the police or other authorities.

Most countries have a legal system that combines both civil and criminal law. Civil law is based on legislation and a body of court decisions, which are known as case law. Criminal law, on the other hand, is based on a code of conduct that a society develops to protect its citizens and regulate commercial activity.

A wide variety of fields are covered by law, including intellectual property (such as patents and copyrights), family and criminal laws. Some fields are relatively new, such as space law, which covers the rights and obligations of nations concerning human activities in outer space.

There are also some fields of law that are very ancient, such as the Roman law or medieval English law. The latter, for instance, was based on the principle of stare decisis, which means that judges should follow past rulings unless they can show good reason why they should not.

The judicial branch of government deals with the enforcement and interpretation of the law. The responsibilities of this branch of government include interpreting the law, conducting trials and hearing appeals. Some judges are elected, while others are appointed by the king or other high officials. Some courts are partisan, while others are not.

In addition to judges, the judicial branch includes prosecutors and defense lawyers, probation officers and public defenders, as well as clerks who oversee a court’s administration and keep records. Other specialized areas of law are administrative law, bankruptcy law and tax law.