The head of government is the person who leads the government of a country. The two major democratic forms of government are parliamentary, headed by a prime minister, developed in the UK[Citation Needed], and presidential, headed by a president, developed in the USA[Citation Needed]. Most other countries in the world have adopted one or other of these[Citation Needed].
Examples of countries with a parliamentary system include Canada, the United Kingdom, Australia, Ireland, Spain, and Japan. Countries with presidential systems of government include the United States, Mexico, South Korea, and many South American and African countries.
In parliamentary governments, the prime minister is always a member of the legislature, and is never the head of state. In the presidential system, the president is never a member of the legislature, and is always the head of state. Many countries with a parliamentary system, however, have a head of state who is also called a "president", but without executive power. Other countries with a parliamentary government have a hereditary monarch as head of state.
Dictatorships and absolute monarchies are headed by one supreme non-elected leader.