Migration refers to the movement of people between locations. It has been influenced by social, economic, military and political factors over time and has contributed to increasing diversity in countries like the US. While most migration occurs over relatively small distances, factors like violence, lack of opportunities, and search for better lives push people to migrate longer distances. Common types of migration include rural-to-urban and movements influenced by seasonal labor demands. The causes and impacts of migration are complex and affect both originating and destination populations.