Head of the state

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.

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 the Commonwealth Realms). 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 Brazil).

Former French president Charles de Gaulle, while developing the current Constitution of France (1958), said the head of state should embody l'esprit de la nation ("the spirit of the nation").

Some academic writers discuss states and governments in terms of "models".

An independent nation state normally has a head of state, and determines the extent of its head's executive powers of government or formal representational functions. In terms, the head of a sovereign, independent state is usually identified as the person who, according to that state's constitution, is the reigning monarch, in the case of a monarchy, or the president, in the case of a republic.

Among the different state constitutions (fundamental laws) that establish different political systems, four major types of heads of state can be distinguished:

...
Wikipedia