Regional socio-economic-geographical systems: approaches to the definition

The article is devoted to the analyses of theoretical approaches towards the definition of the concept "region" in Russian and foreign researches. Research studies of a region as a socio-economic system appears to be sufficiently conventional within the modern socio-economic and geographic science, however the united approach towards theoretical evaluation of the category, its definition and its forming subsystems does not still exists. The authors put emphasis on a topological approach towards the definition of the concept "the regional social, economic and geographical system