On this episode of the Agenda, we will be talking to the man who is trying to solve the world's refugee crisis. Filippo Grandi is head of the United Nations Refugee Agency the UNHCR. His job has been described as a Herculean task but Grandi, who has been held this role for four years, is a man on a mission. A humanitarian with a touch of the diplomat, he is determined to make a difference. At his office headquarters in Geneva Stephen Cole began by asking him to define the difference between a refugee and migrant.