Law is a complex, interrelated set of institutions and rules aimed at regulating human conduct. It influences politics, economics, history and society in many ways, as well as establishing order and stability. Its precise definition is debated, but it is broadly accepted that the term relates to a set of principles and guidelines for controlling behavior. Whether it is in the form of a constitution, written or tacit, a political system, political party, or an individual’s conscience, law governs society and human interaction.

The most common function of law is to maintain social order and protect human rights. The law ensures that citizens are treated fairly by ensuring that no one can exercise excessive power over others. In the United States, this is achieved through a constitutional structure that divides executive, legislative and judicial powers. This arrangement, known as the separation of powers, ensures that no one person can gain absolute power over the other branches of government and that laws are not influenced by personal, ideological or partisan considerations. It is also the framework that prevents laws from being manipulated by those who want to take advantage of the system.

A nation’s legal system is a reflection of the social context in which it exists. It varies greatly from country to country, reflecting differences in cultural and social structures, and in the power relationships between people and governments. Many nations rely on law to preserve the status quo, while others use it as a tool to promote democracy and social change.

Some of the most important laws are international treaties, including those related to human rights and the environment. Other important laws are criminal and civil procedure, which outlines the rules that must be followed in trials or appeals. Other areas of law include labour law, which relates to the tripartite industrial relationship between worker, employer and trade unions, and property law, which regulates ownership and possession condition of real estate or private assets.

In a common law system, judicial decisions are considered to be as valid as legislative statutes and executive regulations. In this type of system, the principle of stare decisis (Latin for “to stand by decisions”) means that decisions made by higher courts bind lower courts to assure consistency in court decisions. In contrast, in a civil law system, legislative statutes are typically more detailed than judicial decisions, and judges’ decisions may only apply to the particular case before them. Nonetheless, both types of systems depend on precedent to provide consistency.