Human migration is different compared to the animal migration. It is the movement of people from one place to another to seek permanent or semi-permanent residence. The movement usually happens across the political boundary. It could be a semi-permanent movement, if you are a seasonal farm laborer. The movement can be voluntary and involuntary.
These terms are used for international migration or migration from one country to another. Immigration is coming from one country to another and emigration is going from one country to another. For example; immigration of Hindus from Bangladesh to India and emigration of Indians to united states.
Human migration is the movement of people from one place to another and the intentions of settling to the new location can either be permanent or temporary. This type of movement usually covers a long distance, probably from one country to another. Nomadic movements are not considered as migration as their intention is not to settle in any new place but it’s all seasonal.
Assimilation is the integration of two dissimilar cultures into a single culture comprising characteristics of both. When a minority ethnic group is assimilated into the dominant culture, the minority group loses its distinctiveness.