Islamic Republic — Countries like Afghanistan, Pakistan, Iran are republics governed in accordance with Islamic law.

Arab Republic — for example, Syria, where Arabs are the overwhelming majority of total population.

People's Republic, or Single-party state — Countries like China, Vietnam are meant to be governed for and by the people, but with indirect elections.

Democratic Republic — is a republic where the people elect their representatives and may engage in some forms of popular referenda. Examples include the United States of America.

A monarchy is a form of government in which all political power is absolutely or nominally lodged with an individual, known as a monarch ("single ruler"), or king (male), queen (female).

As a political entity, the monarch is the head of state, generally until their death or abdication, and "is wholly set apart from all other members of the state.

A constitutional monarchy is a form of monarchical government established under a constitutional system which acknowledges an elected or hereditary monarch as head of state. An absolute monarchy is a monarchical form of government where the ruler has the power to rule his or her land or country and its citizens freely, with no laws or legally-organized direct opposition in force.

State system – is the way of territory organization of one state or several states, united in one union. It is interconnection and interdependence of state and his elements (territories), fixed in the Constitution of the country. State system characterizes the territory organization of state power. However, different social organizations, parties and communion can not be regarded as types of state system.

The types of the state are federation, a confederation, a unitary state, empire.

A unitary state is a sovereign state governed as one single unit in which the central government is supreme and any administrative divisions (subnational units) exercise only powers that the central government chooses to delegate.

A federation, also known as a federal state, is a type of sovereign state characterized by a union of partially self-governing states united by the central (federal) government.

A confederation is an association of sovereign member states that by treaty have delegated certain of their competences (or powers) to common institutions, in order to coordinate their policies in a number of areas, without constituting a new state on top of the member states. Under international law a confederation respects the sovereignty of its members and its constituting treaty can only be changed by unanimous agreement.

Empire is a geographically extensive group of states and peoples (ethnic groups) united and ruled either by a monarch (emperor, empress) or an oligarchy.

According to another classification states can be divided into:

• Sovereign state, a sovereign political entity in international public law

• Member state, a member of an international organisation

• Federated state, a political entity forming part of a federal sovereign state

• Nation state, a state which coincides with a nation

• Rechtsstaat, the legal state (constitutional state, state subordinated to law)