Change of place of residence (permanent or temporary) in the territory of Poland, related to crossing the administrative border of a gmina, including - in case of urban-rural gminas - changes of the place of residence within a gmina, i.e. from rural to urban areas and vice versa. Arrival (i.e. registration) in a given administrative unit with the purpose of residing there is called migration inflow, whilst departure with the purpose of residing in another administrative unit is called migration outflow.
In internal migration following types are distinguished:
- intervoivodship - all population's movements from one voivodship to another;
- intravoivodship - all population's movements are within the same voivodship;
- interpowiat - all population's movements from one powiat to another;
- intrapowiat - all population's movements are within the same powiat.
When classifying the internal migrations in terms of administrative character of the territories among which there was a movement, following directions of migration are distinguished:
- from urban to rural areas,
- from rural to urban areas,
- from one urban area to another,
- from one rural area to another (it concerns migration between rural parts of the gminas, not between particular rural localities).
In reference to character of stay, following type of migration are distinguished:
- migration for permanent residence (involving registration for permanent stay)
- migration for temporary stay (lasting more that 3 months; for data up to 2005 - for more than 2 months).