It led to the ability to sustain a large population within the same geographic locale. Agriculture triggered a population explosion for those societies who adopted the practice.
Cities are a center of trade and manufacturing, in which they often do business with nearby cities.
Typically a pyramid-shaped social structure with the most important person at the top and the least important at the bottom. Slavery on average was about 7 years per person and mostly involved domestic servitude. Metal was a technological breakthrough that advanced agriculture, civil engineering, warfare, and the manufacturing of finished goods such as household wares. These new metals had greater durability and created deadlier weapons on the battlefields. We call this style Allegory.