Public law is concerned with the relationship between the state and individuals, it is not usually concerned with disputes between individuals, unlike contract law or tort law. Public law is concerned with how power is divided and used by the state. It seeks to regulate misuse of this power.
Unlike in countries such as America, in the UK we do not have a single constitution; power is often exercised through convention rather than a written document. Public power is exercised not only exercised by convention though; statute often intervenes, along with the law of the courts and agreements which the country makes from time to time.
We can divide public law into constitutional law: that of primary government organs, and administrative law: that of agencies who use regulatory power. A local authority would be a good example of this.
We’ll talk more about constitutions later in the section, but for now, we must understand how the power-exerting bodies are constructed in the UK.