This chapter deals essentially with internal migration, also covering some types of cross-border migration, even though these are theoretically international movements. The chapter is concerned with voluntary migration for employment. It does not include displacement caused by development projects, conflict and civil unrest. Nor does it attempt to provide a comprehensive view on trafficking in human beings, which has become a subject in its own right. However, the divisions between migration for work and other kinds of migration are not watertight, and several forms of migration for work are akin to trafficking in human beings, especially in migration involving vulnerable and often marginalized groups, such as women, children and ethnic minorities. Some aspects of migration that overlap with trafficking will therefore be touched upon