The difference between migrants, immigrants and refugees:
Migrant : a worker who moves from place to place to do seasonal work.
Immigrant : a person who comes to live permanently in a foreign country.
Refugee : a person who has been forced to leave their country in order to escape war, persecution, or natural disaster.
Somewhere between those three categories are those that are displaced, fleeing their homeland in fear of their livelihood without being granted official asylum. This is reminiscent of the kind of situation we now see in Lebanon.
The United Nations is the leading organization in the world that helps refugees. The UNHCR is deployed in parts of the world where the refugee situation reaches epidemic proportions. For reasons that are not quite clear to me, it seems that there are certain displaced people who are not given refugee status. One reason I can surmise is that they don’t come from a conflict zone. As was the case in Greece when I met people traveling through the route from the Middle East to Europe through Turkey, those that didn't come from Iraq, Afghanistan, Syria or Somalia were not granted refugee status and were not permitted into the official UNHCR camps. It was an issue with others who might have been from a conflict zone or war torn country but who had no proof in the form of identification.