There was a time when people did not live in cities, but moved from place to place depending upon where they could find the most plants and animals to eat.When people learned to farm and raise their own animals, they no longer needed to hunt for food. Now many people could live in the same place without having to fight to have enough food for everyone. When many people moved to one area, the area became known as a city.
Cities were the beginning of civilization. Since farming needs water, most of the first cities were located near rivers or some source of water. People who lived in cities had time to concentrate on things other than food. They began inventing tools, weaving clothes, building, teaching children to read and write, and so on. As cities grew, people chose leaders to make rules so that everyone could work together peacefully. This marked the beginning of an organized system of government. So, a civilization is a group living within a certain area that makes advances in any fields of knowledge.