Final answer:
Migration is the process of moving from one place to another. When someone moves to the United States from another country, it is called immigration. Immigration is a form of voluntary migration.
Step-by-step explanation:
Migration is the process of moving from one place to another. When someone moves to the United States from another country, it is called immigration. Immigration is a form of voluntary migration because it is the act of individuals choosing to move to another country in search of work, opportunities, or a better life.