In practise, the fringes of different types of migratory flows and different forms of mobility are not separated from each other, but do relate to each other. It is suggested that research should focus much more on such interrelations instead of trying to separate the different forms of migration and mobility analytically. Of special interest here is the entangledness of the various forms of migration and mobility, especially when it comes to the mixture of stock- and flow population. It is mostly through the practises of migrants in the cities that urban transformation is spurred and that makes it more powerful in international comparison.