Law is the set of rules that a community develops to regulate its behavior, deal with crime and business agreements and define rights and duties between people. It is also a term used to describe the professions that deal with these systems, such as lawyers and judges.
Legal systems vary greatly, but most are based on custom and a history of judicial decisions. In common law jurisdictions, for example, several stages are required to determine “what the law is” in a given case: one must ascertain the facts of the case; find any relevant statutes and cases; extract and analyze the principles, analogies and statements from the past decisions; and combine them to determine how the court is likely to rule on the facts of the present case. More recent decisions and those by higher courts carry more weight than earlier ones.
A nation’s laws can serve a variety of purposes: to keep the peace, maintain the status quo, protect minorities against majorities, promote social justice and provide for orderly social change. Different legal systems achieve these goals in various ways, and some are more successful than others. For instance, an authoritarian regime may keep the peace but oppress minorities and its own citizens. In contrast, a constitutional democracy may provide for checks and balances and guarantee core human, property and other rights to all its citizens. The law is also an important mediator of relations between governments and their citizens, between private businesses and their customers, and between private individuals.