Law is a system of rules that a society or government develops in order to deal with crime, business agreements and social relationships. It can also refer to a profession which involves advising people about the law, representing them in court and administering punishments. A person who practices law is known as a lawyer or a barrister. He or she can be called an Esquire to show respect, or Doctor of Law to show a degree of legal scholarship.

The precise definition of law is a matter of ongoing debate. However, it is generally agreed that a law is a system of rules that a community accepts as binding on its members. Laws are often formulated in the form of written codes, statutes or rules. These may be derived from ancient precedent, custom and practice, religious teachings or the will of God.

In modern times, the law has become increasingly complex and wide-ranging. It can be divided into criminal law, civil law and family law. Criminal law relates to the punishment of behaviour considered to be harmful to social order. It includes laws against murder, robbery, fraud and breach of confidence. Civil law is a broad area that encompasses the resolution of lawsuits (disputes) between individuals and groups. It can be split into several further areas, including contract law, tort law and property law.

Traditionally, there has been a distinction between common law and civil law. Civil law was developed in Europe to simplify commercial transactions. Codes were compiled so that merchants could operate across national boundaries with a single set of rules. This was a major advance on the many splintered facets of local law that existed previously. Today there is a trend towards common law being combined with civil law.

The main purposes of law are establishing standards, maintaining order, resolving disputes and protecting liberty and rights. However, there are some limitations on the power of the law. For example, it cannot force people to do things that are against their natural consciences or impose obligations beyond their resources.

In addition to its practical applications, the study of law is a fascinating subject in its own right. It provides a source of scholarly inquiry into legal history, philosophy, economic analysis and sociology. It also raises profound issues concerning equality, fairness and justice.