The law shapes politics, economics and history in many ways and serves as a mediator of relations among people. Legal systems vary from nation to nation and some are better at serving their principal functions of keeping the peace, maintaining the status quo and protecting human rights.
The basic law of a state or nation is its constitution. It is complemented by statutes and regulations (including administrative decisions), and by judicial interpretations of them, which are given force under the doctrine of stare decisis. The legal profession is organized into various specialties. Lawyers may be called barristers, solicitors or judges. There are also titles of respect such as Esquire, which designates a high level of the profession.
In most civil law jurisdictions, laws are written and consolidated in codes that are easy to read for citizens and jurists. These laws reflect a logical and dynamic taxonomy developed from Roman law and adapted to changes in social situations. They emphasize cooperation and mutual help. In contrast, common law systems, with their focus on judging individual cases according to the facts presented, are less structured and rely more on precedent. Despite these differences, civil and common law have historically coexisted in many countries. Today, however, there are signs that civil and common law are converging. In some areas, like aviation and railways, the federal government has created a comprehensive scheme of law that preempts all state law. In other areas, such as antitrust and family law, a small number of federal statutes interact with a much larger body of state law.