Law is commonly understood as a system of rules that are created and enforced through social or governmental institutions to regulate conduct, although its precise definition is a matter of longstanding debate. It has been variously described as a science and the art of justice. The definition of law is a set of conduct rules established by an authority, custom or agreement. An example of law is don't drink and drive. "Law." Your Dictionary. Love To Know. It requires measures to ensure adherence to the principles of supremacy of the law, equality before the law, accountability to the law, fairness in the application of the law, separation of powers, participation in decision-making, legal certainty, avoidance of arbitrariness, and procedural and legal transparency. As citizens we respect the laws because they are clearly communicated and fairly enforced. Everyone is held accountable to the same laws, and those laws protect our fundamental rights. This is the foundation of the rule of law in the United States. The bill has to be voted on by both houses of Congress: the House of Representatives and the Senate. If they both vote for the bill to become a law, the bill is sent to the President of the United States. He or she can choose whether or not to sign the bill. If the President signs the bill, it becomes a law.