Endogamy is the restriction of mate selection to people within the same group, which can be defined by factors such as race, ethnicity, religion, caste, or social class. It is a common practice in many societies around the world, and it can have a significant impact on the genetic makeup and social structure of a population.
There are a number of reasons why people may practice endogamy. In some cases, it may be due to religious or cultural beliefs that prohibit marriage outside of a particular group. In other cases, it may be due to social or economic factors, such as the desire to maintain wealth or status within a particular community. Endogamy can also be a way of preserving cultural identity and traditions.