Push-Pull Factors: These are factors that either push people out of their home countries (such as poverty or political instability) or pull them towards other countries (such as job opportunities or better living conditions).
Border Control: The enforcement activities carried out by a country's authorities at its borders to regulate the movement of people, goods, and services. This can involve checkpoints, patrols, and inspections.
Naturalization: The process through which non-citizens become citizens of a country. It usually involves fulfilling legal requirements such as residency, language proficiency, and passing citizenship tests.