Law is the rules that govern a community or group of people. These rules, which must be agreed upon and enforced by the group, can cover everything from property rights to crimes. Law can be defined in many ways, but it is generally agreed that it involves a set of social rules that members must obey. In the modern world, law is largely regulated by government agencies, which are often overseen by federal courts. This system can be abused by corrupt politicians or bureaucrats, but it also has the potential to provide an effective check on power and limit abuse of individual rights.
A law may be a formal agreement between two or more parties or it could be a body of written or unwritten rules. In the United States, most ideas for laws are first introduced as bills in Congress. These bills are labeled with an abbreviation of the House of Representatives or Senate where they were introduced, and a number that indicates its place in the order of bills presented during a legislative session. Bills that deal with issues that affect the public become Public Laws, or Acts, if approved by both houses of Congress and signed into effect by the President.
Different legal systems have evolved in response to the varied needs of societies. These include the need to keep the peace, preserve the status quo, protect minorities against majorities, and promote social justice. Some systems serve one or more of these purposes more effectively than others.
For example, an authoritarian regime may be effective at keeping the peace and maintaining stability, but it might oppress minorities or political opponents. In contrast, a democracy may allow its citizens to freely express their beliefs and choose the leaders they want to represent them.
Law can be based on religious belief or books, such as the Jewish Halakha, Islamic Sharia, and Christian Canon law. It can also be based on the practices of a particular society, such as the agrarian system in ancient Babylonia or the colonial systems of Europe.
The law can also be a collection of decisions based on legal precedent, a history of judicial rulings that determine the criteria used to evaluate new cases. Regardless of whether these precedents are unfair, outdated, or biased, they remain the basis for future rulings until societal changes prompt a judicial body to overturn them. A judicial body may also make its own law, which is known as case law or common law. This is an important part of the American judicial system, and it is often cited as the basis for due process, a legal concept that requires anyone who is subject to a court decision to be given a full hearing before that decision can be made.