Iran's government is defined as a theocratic republic. A theocracy is ruled by religious leaders who are believed to be acting on behalf of their deity. A republic is run by a democratically elected leader. In Iran, the government is run by an elected president, parliament, local councils and an "Assembly of Experts"- all of which must follow Islamic principles.
The government in Iran is a unitary state with a presidential system. The capital of Iran is Tehran, and has a population of 76.42 million.
Because of its theocratic elements, Iran is typically considered an Illiberal Democracy (as opposed to Liberal Democracies like the United States, France, Germany, et al.). That is to say that while there are certain trappings of democracy, they are not sufficient to create a truly democratic atmosphere. Several things that Iran has which make it a democracy include: regular voting periods, different candidates, and different parties with conflicting interests. Several things that Iran has, which preclude it from being a Liberal Democracy include: suppression of political expression, unelected leadership (in the form of the Supreme Leader and his council), repression of political parties, widespread voting fraud, restrictions on the freedom of speech and in the press, required loyalty oaths (this prevents members of Parliament from speaking out on issues for minority constituencies which have been harassed by the government), and unbalanced campaigning (where the "desirable" candidate can slander other candidates, but cannot himself be publicly slandered to the same extent).
Iran has a mixed econmy.
Monarchy
`Not very stable
The most important form of leadership on Iran is the Islamic hierarchy that has the final say over government activities. The top religious ruler in Iran has the title of Ayatollah.
Iran had a monarchy before 1900. Qajar monarchy.
Mohammad Reza Shah Pahlavi was the Shah of Iran from 1941-79. He was deposed by the Islamic Revolution in 1979. After the Islamic Revolution, Iran changed its form of government to an Islamic Republic, and control was given to the leader of the Revolution: Ayatollah Khomeini. This new form of government is the form of government in present-day Iran, as well.
Afghanistan, Saudi Arabia, Iran, Pakistan etc
Shiates rule the government of Iran.
The government of Iran is based on Islam. Citizens of Iran are affected by the decisions and policies of the Islamic clergy.
Half of Iran's government and the private sector is half of the Iranian economy. The Iranian government that Iran is trying to privatize it.
Iran is governed by an Islamic theocracy.
Islamic Republic of Iran
The Political beliefs of the government in Iran center around their religion of Islam. Laws & policies in Iran are made in line with their interpretation of the Qur'an, which is why Iran is considered a theocracy. However, it should be noted that a significant portion of Iranians would prefer a more secular and democratic form of government; the problem is that protests are illegal in Iran and all political candidates must be "acceptable" to the Ayatollahs.