On the basis of territorial division of authority, the states are classified into Unitary and Federal and on the basis of the nature of authority into Liberal and Totalitarian. 

A confederation is a union of sovereign states, united for purposes of common action often in relation to other states.

i. An authoritarian regime has one ruler, a leader or a committee, the same as a totalitarian, only in an extreme way. The totalitarian has charisma over his people while the authoritarian imposes fear over those who oppose and rewards those that are loyal to him.

ii. The totalitarian is more of a divine ideologist who will save the people, while the authoritarian is focused more on control and status quo as an individualist. The totalitarian uses his prophetic leadership to drive the people, while the authoritarian uses political parties, mass organizations, and other propagandas to make the people follow him.

It is the president who makes his government and he can also unmake it at his own will. 

A convention is a set of agreed, stipulated, or generally accepted standards, norms, social norms, or criteria, often taking the form of a custom. In government, convention is a set of unwritten rules that participants in the government must follow. Eg. The British Constitution.