what does the declaration of the Rights of Man and the Citize say about whom or what has power in a nation

The Declaration of the Rights of the Man and the Citizen was issued in 1789 by the French National Constituent Assembly. It is a document, which arose from the French Revolution, and contains the human civil rights which are stated to be universal, applicable everywhere and everytime.

The declaration includes the philoshophycal and political ideas of the Enlightment. The following two are the most important ones:

The social contract concept of Rousseau which states that citizens hold the power of a nation and grant it to representatives and goverments through suffrage. It was a vision that clearly opposed the existent absolut monarchies and ancient regime systems that were operating at the moment. The division of powers by Montesquieu, which stated that the power of a nation should be divided in three independent branches: legislative, executive and judiciary, implemented together with a balance system that ensures that none of them gathers enough power to overrule the other branches.