This chapter addresses human trafficking in four sections: the nature and extent of the harm; the structure of human trafficking (considered in terms of source, transit and market); regulation and control; and finally a discussion about human trafficking as illicit business. The definitions and common types of human trafficking are reviewed, along with observations on how human trafficking occurs, including drivers, structures and routines. Interview studies with human traffickers are considered in the final section. The first-hand testimonies of traffickers are used to further develop the overall theoretical premise of the book: that when thinking and talking about trafficking, including human trafficking, participants use a framework of illicit business enterprise that has rationalising, neutralising and compartmentalising effects for them.