What do you mean by three generations of immigrants?

Immigration is population migration (now refers to living abroad), which has a wide range of activities, such as colonizing America and immigrating to Europe and America. Immigrants are individuals or groups who have moved from one country or region to another for a long time, engaged in livelihood economic activities in the place where they moved, and were given local social obligations.

Three generations of immigrants, that is, the third generation of immigrants, refer to the grandchildren of the first generation of immigrants.