One of the issues that have been most prominent in relation to migration and their presence in schools in recent decades in Spain has been the distribution of students of foreign nationality in different schools and associated processes of segregation and inequality and inter- intracentros. The phenomenon is amply documented in the international context. However, it can be said that there is no widespread agreement on how to talk and how to approach the study of these dynamics.

You can not say that it is an unknown phenomenon and lacks Speakers to the research community and the public, in general, not yet known. Since 2000, about and for the case of Spain, the reference to the concentration of students of foreign nationality in certain centers, mainly public intensifies in the daily press.

On these issues we reflect on the present work, although without seeking homogeneity of guidelines or conclusions, for work done from different disciplines and with varied methodological approaches meet. What has been tried has been covering the different nuances that the words "concentration" and "segregation" may have. The study not only focuses on the segregations that relate the differences and distinctions between centers in relation to the phenomenon of the presence of "migration" in school because segregations within the centers themselves are as important as the above.