What is an advanced civilization?

Advanced civilizations are societies that started thinking about a lot of other things than just simply gathering food very early in time. They had cities, an administration, and a division of work among the people. Advanced civilizations developed the calendar and laid the foundation for many sciences. A total of 25 advanced civilizations include those of the Sumerians, Babylonians, and Assyrians in Mesopotamia—what we today know as Iraq—Egypt, Persia, China, the Indus valley civilization, several cultures on the American continent, and the Minoan in Europe.