The course explores the concept "boundary"in contemporary sociology and the practices applied when crossing boundaries. We will discuss, among others, the diverse meanings of the concept "boundary" (social, symbolic, spatial, class, ethnic, national, etc.), how they are signified, maintained and blurred in daily life. We will examine the strategies used by social actors during boundary crossing in various social contexts. These and other issues will be examined through the theoretical lenses of selected approaches in the sociology of practice and of culture, especially the work of Lamont, Swidler, Bourdieu, Boltanski, Latour, Goffman.