This document discusses global flows of people through migration and tourism. It defines migrants as populations on the move, distinguishing vagabonds who move out of necessity from tourists who move by choice. International migration has four components: in-migration, return migration, out-migration of nationals, and out-migration of foreigners. While migration policies have not been fully liberalized due to economic and security concerns, barriers to migration have been selectively reduced in many countries due to labor shortages and other factors. The document also discusses refugees, labor migrants, flows of migrants to different regions, diasporas, brain drain, and the network society theory of Manuel Castells.