Civilization is a term that describes a complex way of life with many facets. The key aspects are urban areas, shared methods of communication, administrative infrastructure and division of labor. Some people believe that civilization also includes a culture and religion.
The idea of what constitutes a civilization changes over time, and it is impossible to put together a definitive checklist. However, the emergence of civilizations seems to happen at roughly the same time around the world and has a similar set of characteristics. It also appears that the defining characteristics of civilization are universal, although it may be difficult to find examples outside the Middle East and Mediterranean region.
The earliest civilizations began in the Neolithic period in Mesopotamia and the Indus Valley and later developed into empires that included the Akkadian Empire, Egypt and the Old Kingdom of Sumer. In addition, the Abbasid Caliphate ruled Iran, Iraq and parts of North Africa at one point.
One of the first steps in becoming a civilization was to become sedentary, moving to permanent settlements and building cities that allowed large numbers of people to live in close proximity. This provided more space for farming and also allowed for a greater division of labor so that people could specialize in their craft. These specialties, in turn, allowed people to produce surplus artifacts that could be traded with other communities.
Other key features of civilization include the development of an agricultural surplus and a system of governance that allows people to vote and have representatives who represent their interests in government. The earliest systems of government were often repressive and autocratic, but the spread of agriculture and other technological advances allowed more people to have more freedom and to develop cultural expressions that are part of civilizations.
A final element is that a civilization must have some economic hierarchy that separates wealthy from poor citizens. Typically this involves a class system in which those who own land or work as craftspeople have more wealth than those without property or jobs.
This class structure is usually based on income, but it can also be based on social status or type of work done. Traditionally, Western civilizations have divided people into three or four economic classes: upper, middle and lower. In ancient Rome, the wealthy owned land and the lower classes worked for the state as serfs.