Law is a system of rules that regulates the conduct of people within a community and is enforced by a controlling authority through penalties. The rules are typically based on the moral values of the community. Law is often viewed as something that is separate from religion, politics or personal beliefs. However, many countries, including the United States, have religious and political components to their laws.

The laws in most countries are written by groups of politicians called a legislature or parliament, who are elected (chosen) by the citizens of a country to represent them in making and enforcing laws. This is why it is important for the people who elect these legislative bodies to be well informed about the issues and how laws are made.

In most legal systems, the law is based on a combination of decisions made by judges in court cases and precedents set by earlier rulings. The principle of precedent is called stare decisis. This means that a judge must follow the law set by previous judges in deciding a case, even if the earlier decision was made on different facts.

The most common types of law are criminal, civil and constitutional law. Criminal law deals with the use of courts to punish people who break laws. Civil law includes contracts, property and torts. Constitutional law focuses on the rights of citizens and the role of a government. This can include things like the separation of powers, and the right to free speech.

People can also make a claim for compensation (repayment) when they are injured or their property is damaged by another person. This type of law is known as tort law. Intellectual property law protects the rights of people who create art, music and literature. It also covers inventions that are created. Laws that deal with the business world, such as contracts and bankruptcy, are called commercial law. The law that governs the safety of airplanes is called aviation law.

A special kind of law is environmental law, which is intended to protect the environment. This law is framed by international agreements, such as the Kyoto Protocol and the International Civil Aviation Organization’s standards for the operation of aircraft.

In addition to the laws that control people’s actions, there are a variety of other types of law, such as administrative law, which involves regulations and procedures; maritime law; patent law, which is the law covering inventions; and trust law, which is used to manage assets for retirement. The law is also influenced by science, which is the body of knowledge about how the natural world works. For example, the law of gravity is a scientific fact that describes how objects (like apples and the Earth) interact with each other in a certain circumstance. The law of gravity is the same everywhere in the universe, but would not apply if the circumstances were different. This is because the force that causes an apple to fall down from a tree depends on the mass of the apple and the distance between it and the ground.