Put simply, child trafficking is the movement of a child, within a country or across borders for exploitative purposes.
Last week, the Home Office's child exploitation and online protection centre said one in five suspected victims of child trafficking were missing from care.
Beijing launched a widely publicised crackdown on child trafficking this year after an online campaign urged residents to photograph street children to help parents identify kidnapped youngsters.
The United Nations children's Fund says some Haitian children are missing from hospitals, raising concerns of child trafficking after last week's earthquake separated thousands of families.
Earlier this month, police uncovered a child trafficking gang in Lebanon after a mayor, his wife, a midwife and a doctor at hospital in the Bekaa valley were arrested for selling newly-born children.