Law is a system of rules, enforceable by authorities or by consensus, that govern the conduct of people and companies. Laws define rights and obligations, establish standards, control the economy and mediate relations between people. The term has a broad range of meanings: it may refer to laws made by governments, to the set of all legal codes or to particular fields such as contract law, property law or criminal law. It can also mean a set of rules that people follow in their daily lives, such as the laws of nature or the laws of self-preservation. Lastly, the term can refer to a profession that involves advising people about the law or representing them in court.
In legal systems with a common law tradition, decisions by courts are recognised as law and placed on equal footing with legislative statutes and executive regulations. This is known as the doctrine of stare decisis. In this way decisions by higher courts bind lower ones to assure that similar cases reach comparable results. In contrast, civil law systems typically place more emphasis on legislative statutes and less on judicial decisions.
Throughout history, legal systems have adapted and grown to reflect the societies in which they exist. These changes have been driven by social, economic and political factors: felt necessities of a given age or period, current moral and political theories, intuitions of public policy and even avowed or unconscious prejudices all play a part in determining what the law is. It is difficult, therefore, to regard law as a collection of logical deductions.
The most fundamental aspects of the law are those that relate to the exercise of power. The principles of supremacy, equality and accountability to the law are essential pillars for the rule of law. These can be translated into specific measures by enshrining in the constitution, written or tacit, those policies and values that govern the administration of the state.
Other important areas of the law are those that regulate people’s relations with each other and their activities with the environment. For example, property laws determine people’s rights and duties toward tangible and intangible possessions. Commercial law, such as company law, banking law and financial regulation, regulate the exchange of goods and services for money or other value. These and other aspects of the law are reflected in laws on taxation, labour relations, health and safety and consumer protection.