Skip to main content

International Migration is the movement of a person or a group of persons across an international border. It is a population movement, encompassing any kind of movement of people, whatever its length, composition and causes; it includes migration of refugees, other external displaced persons, migrant workers, and persons moving for other purposes, including study and family reunification (see Glossary on Migration, IOM, 2011). The IOM Constitution, in particular, notes that “international migration also includes that of refugees, displaced persons and other individuals compelled to leave their homelands” and calls for “facilitating the emigration of persons who desire to migrate to countries where they may achieve self-dependence through their employment and live with their families in dignity and self-respect” (IOM (1989:9) Constitution of the International Organization for Migration).

Mixed Migration is also referred to as irregular migration. They are synonyms. Irregular migration can be defined as migration that occurs outside the regulatory norms of the origin, transit, or destination country. Although clandestine migration attracts the most attention, it is widely acknowledged that bigger is the number of migrants who arrive legally (for example, on the basis of tourist or student visas) and then overstay the period for which their visas/permits are valid. The term Mixed Migration puts the individual at the center of the discourse and calls for individual screening to identify protection and assistance needs. The term Mixed Migration is also a reminder of the complexity of the phenomenon. For instance, people might cross one border regularly and another irregularly. It, nevertheless, overlooks overstaying and focuses the attention on clandestine movements. Regardless of the term used, it is important delinking migration from insecurity. As observed by the UN special rapporteur on the human rights of migrants, ‘’… the smuggling of migrants may constitute a criminal offence, irregular migration does not, and should thus not be linked to security issues and crime’’. Irregular migration should be decriminalized (François Crépeau (2013) Report of the Special Rapporteur on the human rights of migrants, UN Doc. A/HRC/23/46).


Forced Migration is a general term that refers to the movements of refugees and internally displaced people due to conflicts as well as people displaced by natural or environmental disasters, famine, or development projects internally or externally (see Glossary on Migration, IOM, 2011). Those displaced externally by natural or environmental disasters, famine, or development projects are not refugees.


Return migration:  In the context of international migration, the movement of persons returning to their country of origin after having moved away from their place of habitual residence and crossed an international border. In the context of internal migration, the movement of persons returning to their place of habitual residence after having moved away from it.  Note: UNDESA defines returning migrants as “persons returning to their country of citizenship after having been international migrants (whether short term or long-term) in another country and who are intending to stay in the country for at least one year (Recommendation on Statistics of International Migration, Revision 1, 1998, p. 94).

Circular migration:  The fluid movement of people between countries, including temporary or long-term movement which may be beneficial to all involved, if occurring voluntarily and linked to the labour needs of countries of origin and destination.

Integration: While the term is used and understood differently in different countries and contexts, “integration” can be defined as the process by which migrants become accepted into society, both as individuals and as groups. It generally refers to a two-way process of adaptation by migrants and host societies, while the particular requirements for acceptance by a host society vary from country to country. Integration does not necessarily imply permanent settlement. It does, however, imply consideration of the rights and obligations of migrants and host societies, of access to different kinds of services and the labour market, and of identification and respect for a core set of values that bind migrants and host communities in a common purpose. Local integration is one of the three durable solutions to address the plight of refugees. It may also be applied to victims of trafficking and unaccompanied children.

Residence: The act or fact of living in a given place for some time; the place where one actually lives as distinguished from a domicile. Residence usually just means bodily presence as an inhabitant in a given place, while domicile usually requires bodily presence and an intention to make the place one’s home. A person thus may have more than one residence at a time but only one domicile.

Nationality: Legal bond between an individual and a State. The International Court of Justice defined nationality in the Nottebohm case, 1955, as “…a legal bond having as its basis a social fact of attachment, a genuine connection of existence, interests and sentiments, together with the existence of reciprocal rights and duties…the individual upon whom it is conferred, either directly by law or as a result of the act of the authorities, is in fact more closely connected with the population of the State conferring the nationality than with any other State.” According to Art. 1, Hague Convention on Certain Questions Relating to the Conflict of Nationality Laws, 1930 “it is for each State to determine under its own laws who are its nationals. This law shall be recognized by other States in so far as it is consistent with international conventions, international custom, and the principles of law generally recognized with regard to nationality.” The tie of nationality confers individual rights and imposes obligations that a State reserves for its population. Founded on the principle of personal jurisdiction of a State, nationality carries with it certain consequences as regards migration such as the right of a State to protect its nationals against violations of their individual rights committed by foreign authorities (particularly by means of diplomatic protection), the duty to accept its nationals onto its territory, and the prohibition to expel them.