<P> A head of state (or chief of state) is the public persona that officially represents the national unity and legitimacy of a sovereign state . Depending on the country's form of government and separation of powers, the head of state may be a ceremonial figurehead or concurrently the head of government . </P> <P> In countries with parliamentary systems, the head of state is typically a ceremonial figurehead that does not actually guide day - to - day government activities or is not empowered to exercise any kind of secular political authority (e.g., Queen Elizabeth II of United Kingdom). In countries where the head of state is also the head of government, the head of state serves as both a public figurehead and the actual highest - ranking political leader who oversees the executive branch (e.g., the President of the United States). </P>

Who is called the head of the state