Law is a system of rules that a government or society sets up to regulate crime, business agreements and social relationships. It is made up of laws that citizens must follow or face punishment for breaking them.
A person who works in a legal system is called a lawyer. The word law is also used to refer to a law that a country has, for example, about murder being against the law in that area.
In a legal system, the decisions of courts are written as law on equal footing with statutes that are passed by governments and other regulations that the executive branch makes. This is known as the doctrine of precedent, or stare decisis.
Justification is a legal normativity issue that typically involves a claim, privilege or power to act in a certain way, or an immunity from harm to the rights of others. These rights are legally valid, if they are recognized by the legislature or courts, but may be invalid if not.
A legal right can be active or passive. For example, a claim to a property can be actively exercised, or it can be a passive right to have an interest in the ownership of the property, for instance, by way of an inheritance. It is also possible to have a right to money or something of value, but not to a specific piece of property. These rights are called claims in rem or rights in personam.