"The head of government is either the highest or second highest official in the executive branch of a sovereign state, a federated state, or a self-governing colony, who often presides over a cabinet, a group of ministers or secretaries who lead executive departments. "Head of government" is often differentiated from "head of state" (as in article 7 of the Vienna Convention on the Law of Treaties, article 1 of the Convention on the Prevention and Punishment of Crimes against Internationally Protected Persons, including Diplomatic Agents and the United Nations protocol list), as they may be separate positions, individuals, or roles depending on the country." - (en.wikipedia.org 08.10.2019)
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