Politics
Vertical integration

In terms of level of vertical integration, political systems can be divided into (from least to most integrated) confederations, federations, and unitary states.

A federation (also known as a federal state) is a political entity characterized by a union of partially self-governing provinces, states, or other regions under a central federal government (federalism). In a federation, the self-governing status of the component states, as well as the division of power between them and the central government, is typically constitutionally entrenched and may not be altered by a unilateral decision of either party, the states or the federal political body. Federations were formed first in Switzerland, then in the United States in 1776, in Canada in 1867 and in Germany in 1871 and in 1901, Australia. Compared to a federation, a confederation has less centralized power.
change_case:english_capital, language:response_language[English]