Emigration is the act of leaving a country or place of residence with the intention of living in another country or place. If you live in Australia and move to live in the U.S. permanently with a intention of getting permanent residency or citizenship, this act is emigration.
What's the difference between emigration and immigration?
Emigration and immigration are both migration from one country or place to another. The difference is emigration indicates the movement of leaving and immigration is the act of entering a foreign country. So if someone from Germany moved to live in the U.S. with permanent residency. He is a immigrant in the U.S. but a emigrant in Germany.