Every nation has at least one person who serves as the ceremonial head of the government.
However, the executive body of any government has a variety of roles that must be fulfilled. How these roles are carried out in different governments varies widely. In some countries, such as Britain, for example, the queen acts as the ceremonial leader and chief of state, while the chief executive and administrator is the Prime Minister. In the United States we have only one president at any given time. The individual in that office, however, must play a number of different roles simultaneously.