Refugee or migrant? Dr Who, Captain Picard weigh in

The hundreds of thousands risking their lives in search of better ones in Europe in recent months, has thrown up a debate over whether to define those fleeing their homes as refugees or migrants.

Celebrities have now weighed in, calling upon the public to use the correct terminology when defining whether a person is a "migrant" or "refugee." When the terms are used interchangeably, this can lead to issues for both communities, according to United Nations High Commissioner for Refugees (UNHCR).

Patrick Stewart, Cate Blanchett, Peter Capaldi
CBS/Jason Merritt/Matthew Horwood | Getty Images Entertainment | Getty Images

Patrick Stewart, well known for his role as Captain Jean-Luc Picard in "Star Trek: The Next Generation", and Peter Capaldi, who plays the character, Doctor Who, in the popular British show, have joined actors Cate Blanchett and Colin Firth in the UNHCR's "#WordsMatter" campaign.

The campaign is aimed at using words with greater care.

In an online video, UNHCR outlines that a "migrant" is someone who "chooses to move" country for reasons such as education or family reunions, while a "refugee" is someone "running for their life," due to conflict or persecution.

Overall, the key difference UNHCR outlines is that migrants are "free to return home," while refugees cannot.

"Words matter – and it matters how the words 'refugee' and 'migrant' are used, because they determine how governments will respond to this crisis," Laura Padoan, external relations associate at UNHCR UK, told CNBC via email.

"Refugees are defined and protected in international law and that means governments have a responsibility to meet those obligations to protect refugees. That is why words matter and why we have enlisted the support of celebrities to help us get across that message."

While European governments are accepting more refugees and have pledged at least a billion euros worth ($1.1 billion) of aid, the migrant crisis has also been controversial.

Four countries voted against the European Union's quota system to relocate refugees last week, however, they were overruled by other leaders.

Nigel Farage, leader of the U.K. Independence Party, told CNBC last week the crisis has the ability to have an even more "disruptive effect on the European Union" and while there's a big cultural and religious debate surrounding the crisis, EU leaders' decision to override those in opposition would lead to "resentment."

At the end of 2014, the UNHCR estimated 59.5 million people were displaced – against their will – due to dangers in their home countries; up from 37.5 million in 2005.

How Europeans have reacted to migrant crisis

In the video, high profile supporters and UNHCR Goodwill ambassadors, define each community and conclude that whether migrant or refugee, all people should be treated with dignity and respect.

"The bottom line is migrants, refugees, we are all human beings. We need to treat all human beings – whether refugee or migrant – with respect and dignity. But meanings matter. Words matter. Your words matter," celebrities say in the UNHCR video.

As the crisis gained momentum in August, Maya Mailer, Oxfam's head of humanitarian policy and campaigns in the U.K., told CNBC it was "primarily a refugee crisis" and countries should make these refugees feel welcome.

"Showing that these (people) are refugees, people like you and me, deserving of protection, and calling on our governments to resettle more refugees and welcome here," Mailer said when describing how to help resolve the crisis on a personal level, while knowing the difference between the two definitions.

Worst European refugee crisis since WWII: Expert
Worst European refugee crisis since WWII: Expert

What society is now facing is the "worst refugee displacement crisis" since the end of World War II, Mailer underlined, adding that what's happening in the Mediterranean is the "most visible manifestation" of the crisis' displacement.

In recent weeks, governments, charities and individuals have all ramped up efforts to help alleviate the migrant crisis.

Migrant Crisis: How ordinary people are helping out

In its reporting of the crisis, CNBC recognizes the situation as involving both "refugees" and "migrants" as it cannot independently verify the status of those seeking asylum.

—By CNBC's Alexandra Gibbs, follow her on Twitter @AlexGibbsy.