Popular sovereignty is the principle that the authority of a state and its government is created and sustained by the consent of its people, through their elected representatives. In simpler terms, it is the idea that the people have the ultimate power and authority in a government.
Popular sovereignty played a significant role in the development of democratic societies, particularly during the age of revolutions. It was a key principle in the American Revolution, as well as in movements for independence and self-governance around the world.