An advanced stage of human social development and organization. Civilization. It is when societies develop complex structures, like cities, laws, and art, to improve how people live together.
A sovereign state functioning as an aggregate of nations. Empire. An empire is a large territory or group of countries under the control of a single ruler or government.
Condition where someone is forbidden to quit their service and is treated like property. Slavery. In history, slavery is when people were owned and forced to work without freedom or rights.
When a person works in a particular occupation most of the time, specialize. In History, specialize means focusing on studying a specific time period or event.