A migrant is any person who goes from one place to another, often seeking work, education, family reunification, etc.
A refugee is someone who is forced to migrate. “Forced migration” is a type of migration in which people are coerced into moving. Coercion can include threats to life and livelihood.
Some people refer to “refugees” as “migrants.” Refugees can indeed be regarded as a special category of migrants because they are also people on the move. But sometimes, the word “migrant” in reference to those fleeing war or danger is used as a rhetorical strategy to indicate the person is migrating out of their own free will to seek economic gain, rather than to seek safety.
However, in international law, the word “refugee” refers to an official status granted by the UN High Commissioner for Refugees (UNHCR) or by a government that has recognized that this person is in harm’s way. According to Article 1 of the 1951 UN Convention and as modified by the 1967 Protocol, a refugee is a person who, “someone who is unable or unwilling to return to their country of origin owing to a well-founded fear of being persecuted for reasons of race, religion, nationality, membership of a particular social group, or political opinion.” This definition implies that in order to gain refugee status, a person must: (1) be outside their home country; (2) have a well-founded fear of persecution; (3) be unable to enjoy the protection of one’s own state.
A refugee is granted asylum in the country to which they have fled. Under international law, no one can be sent to a country or place where they face a risk of being seriously harmed, even if they have crossed a border without permission.
Yet not everyone who is fleeing danger or who claims to be fleeing danger is granted refugee status. When a person has fled, has arrived in another country seeking safety, but has not yet been recognized officially as a refugee, they are called an “asylum seeker.” Not every asylum-seeker will be recognized as a refugee, but every refugee was an asylum-seeker at some point. According to the UNHCR, every year around one million people around the world seek asylum.
A refused asylum seeker is a person whose asylum application has been unsuccessful. Some refused asylum seekers are deported forcibly, others voluntarily leave for another country, or return to the countries they initially left.
For more definitions relating to the problem of forced migration, you can check out this glossary.
For an overview of how sociologists study the refugee crisis, you can check out this online tutorial.