According to whether it crosses national boundaries or not, what kind of population migration does Indian immigration to Australia belong to?

Belonging to barrier-free population migration

Population migration: generally speaking, it refers to the spatial flow of population between two regions, which usually involves the permanent or long-term change of population residence from the place of emigration to the place of emigration. The United Nations Multilingual Demography Dictionary gives a generally accepted definition of population migration, that is, "the geographical or spatial mobility of population between two regions usually involves the change of permanent residence from the place of emigration to the place of emigration." This kind of migration is called permanent migration, which is different from other forms of population flow that do not involve the change of permanent residence. "