Law is a framework within which human society operates, regulating what can and cannot be done. It may be created by a legislative body and codified into statutes or decrees, or it may come through the legal process of court decisions which bind other judges to follow the same rulings, a practice known as precedent. It may also be based on religion or philosophy, and may be codified into religious texts such as the Jewish Halakhah or Islamic Sharia or Christian canon law.
Its fundamental purpose is to govern behavior and ensure that people adhere to the rules of society, whether for moral reasons, or for economic or social practicality. It can be applied by government in the form of criminal or civil laws, by corporations through contract law or commercial law, and by individuals via private contracts. Law can also be a philosophical concept, relating to such things as the nature of the universe and the will of god.
The law is inherently complex. From a methodological perspective, it is normative rather than descriptive, meaning that it prescribes how people ought to behave and what they must or should not be allowed to do. This is distinct from empirical sciences like physics, where laws are descriptive of the world around us and tell how we can understand it. Law is also highly contingent on the shape of our physical world and its limitations, and it cannot mandate behaviours that are improbable or impossible to achieve.
It is also highly dependent on humans and their minds, both to create and enforce it, and to interpret it. This is evident in the fact that different judicial bodies can have wildly differing interpretations of the same set of laws, and in the many debates about how much a judge should be influenced by his or her own personal values or opinions, for example.
Another factor that complicates the study of law is that it can be difficult to verify its content objectively. This is because, as with all knowledge, it depends on humans to record and share it, and as humans are prone to biases and errors, this can lead to problems in the creation and enforcement of laws. For example, it is possible for a judicial decision to be biased against certain groups of people, leading to unjust marginalization or disempowerment, and this may continue until societal changes prompt the judging body to overturn the decision.
Other aspects of law include regulating public utilities and services such as water, energy and transport. It also addresses private businesses that have taken over the provision of these public goods, binding them to varying degrees of responsibility for their actions. Commercial law regulates the buying and selling of goods and services, and corporate law and financial regulation set standards for the amount of capital a company must hold and how it should invest this money. The law of space, which concerns activities and rights in outer space, is an emerging area.