What is the difference between continents, regions, countries, and cities in order to understand the complexities of regions created by civilizations.

Cities are created by groups of individuals or families usually with same linguistic and cultural beliefs forming a union based on their cultures. As people increase in number, they expand the city until it becomes saturated, thus a civilization is born. The over saturated city forces people to migrate to other areas in search of opportunities, where small villages and towns develop into a city, just like the prior.

These groups of cities interact more often due to trading and other services, creating new ways of transportation such as road,bridges,etc. to link up these cities. The accessibility of transportation enables cities to become closer together, more trading occurs which results in alliances and treaties to protect one another. Eventually leading to unification to protect the resources of its land from nomadic tribes and the setting of border lines to protect from neighboring tribes. Thus a country is born.

Contries like the prior stated above, builds it's empire and expands to meet the demands of the people. The expansion of multiple nations along that specific piece of land bring them together as alliances and wars arise to define the landlord of that specific land (region). Thus a region is born, composed of nations.

Multiple countries from multiple regions expand up to the point where all the land have being claimed by nations of different regions thus a continent is born with its predecessors. The ultimate sign of one big civilization composed by groups of civilizations from different civilizations.