When people first started living in communities, they would build their homes close together so they could help each other out and feel safe. These communities were usually small and usually had only a few hundred people living in them.
As time went on and people started figuring out how to grow crops and raise animals, these small communities started to grow bigger. This is because people could now produce more food than they needed, and they could trade it with other communities for things they didn't have.
As cities started to form, people could trade goods more easily, and they didn't have to rely on just their own small community to get what they needed. Cities also attracted people who wanted to work and have access to things like education, religion, and entertainment.
Over time, cities continued to grow and became very large, with millions of people living in them. This is because of advancements in things like transportation and communication, which made it easier for people to move around and stay connected to others, no matter where they were in the city.
Today, we still have big cities, but we also have small towns and rural communities. Each size of community offers its own advantages and disadvantages, and people choose to live where they feel most comfortable.