Once one person can make enough food to feed several people, it becomes possible to build a city, another symptom of civilization. It also leads to the specialization of labor, which in turn leads to trade. Like, if everybody picks berries for a living, there is no reason to trade, because I have berries and you have berries. But if I pick berries for a living and you make hammers, suddenly we have cause to trade. Civilizations are also usually associated with social stratification, centralized government, shared values, generally in the form of religion and writing. And at least in the early days, they were almost always associated with rivers. These days you can just bisect a segment of land horizontally and vertically and boom, build a city.