Law is the set of rules that people or groups agree to follow to regulate behaviour, and to ensure that individuals receive fair treatment. Law shapes politics, economics, history and society in many ways. It is a rich source of scholarly inquiry, in subjects such as legal history, philosophy, economic analysis and sociology.

The law makes clear the enforceable promises that can be made, and the procedures for enforcing sanctions on those who break those promises. It governs the behaviour of governments, businesses and private citizens. It is the core of many important societal functions, including education, healthcare, banking and investment. It also serves as the basis for civil liberties and the constitutions of nations.

Legal scholars study law in different fields to develop and expand the underlying principles that govern society. For example, the study of law in political science and public administration looks at the nature of governmental power and the limits on that power as it relates to the law. This field also focuses on the relationships between governments, businesses and civil society.

Students learn how laws are created and passed, and how courts conduct judicial review of law. For example, students learn how Congress (the lawmaking branch of the United States government) works: how bills are introduced into the Senate and House of Representatives; the process by which each body researches and discusses a bill; how it is amended and voted on; and how it becomes a law. They also learn about the process of a lawsuit, from an initial arraignment (where a defendant is told the charges against him or her) to a final verdict.