Law is a societal structure that regulates the behaviour of individuals and groups. It is a complex system of rules, principles and customs which are difficult to define precisely: it encompasses everything from the rules that govern how a car works to the rights a citizen has when he is charged with a crime. It has been described as an art and a science. It is not possible to empirically verify its content: it is a human invention that depends on the shape of the world and the limitations inherent in it.
The main subjects of law are contract, property and criminal law. However, the subject extends into virtually every aspect of life: competition law deals with businesses that seek to distort market prices at the expense of consumer welfare; consumer protection law is concerned with fair trading terms and conditions; criminal procedure involves the rules that courts must follow in a trial or hearing; and evidence law deals with what can be admitted as evidence.
The study of law is also important for a better understanding of the way in which society operates and the extent to which it is democratic or authoritarian. It engenders debate as to whether judges should be unafraid to use their sense of justice; how much they should be guided by academic doctrine; and what sort of criteria they should employ when making rulings. It also addresses questions of the nature and extent of state power, especially in relation to its encroaching activities in civilian life.