Law is a set of rules that societies or governments create and enforce in order to regulate their activities. Laws may be created by legislative bodies, resulting in statutes and regulations, or by courts, leading to case law. They may be enforced through judicial interpretation of constitutional or legal principles or through executive decrees or administrative action. Private individuals can also create legally binding contracts, which are enforceable by law.
Laws serve four principal purposes: establishing standards, maintaining order, resolving disputes and protecting liberties and rights. Even in well-ordered societies disputes will arise, and law is the way people resolve these conflicts peacefully rather than fighting. For example, if two people claim to own the same piece of property a court will decide who is the real owner. Laws also protect us from threats to our security and health, for example obscene or threatening phone calls are against the law.
Modern law is a complex subject, and there are many different fields of it. Civil law is the type of law practiced in most countries today. It is a comprehensive system of rules and principles usually arranged in codes and easily accessible to citizens and jurists. It traces its roots back millennia, and its codifications are often based on Roman law.
Common law, on the other hand, relies on decisions made by judges who hear cases in the courtroom. Judges are considered to be the depositories of the law, and they must follow a code of conduct in making their decisions. Blackstone argued that a judge must be guided by the constitution and the law, and should only change the law in cases of clear error or misapprehension.