Refugees are a subgroup of the broader category of displaced persons. Environmental refugees (people displaced because of environmental problems such as drought) are not included in the definition of "refugee" under international law, as well as internally displaced people. According to international refugee law, a refugee is someone who seeks refuge in a foreign country because of war and violence, or out of fear of persecution "on account of race, religion, nationality, political opinion, or membership in a particular social group" (to use the terminology from U.S. law).

Until a request for refuge has been accepted, the person is referred to as an asylum seeker. Only after the recognition of the asylum seeker's protection needs, he or she is officially referred to as a refugee and enjoys refugee status, which carries certain rights and obligations according to the legislation of the receiving country.

The practical determination of whether a person is a refugee or not is most often left to certain government agencies within the host country. This can lead to abuse in a country with a very restrictive official immigration policy; for example, that the country will neither recognize the refugee status of the asylum seekers nor see them as legitimate migrants and treat them as illegal aliens.

On the other hand, fraudulent requests in an environment of lax enforcement could lead to improper classification as refugee, resulting in the diversion of resources from those with a genuine need. The percentage of asylum/refugee seekers who do not meet the international standards of special-needs refugee, and for whom resettlement is deemed proper, varies from country to country. Failed asylum applicants are most often deported, sometimes after imprisonment or detention, as in the United Kingdom.

A claim for asylum may also be made onshore, usually after making an unauthorized arrival. Some governments are relatively tolerant and accepting of onshore asylum claims; other governments will not only refuse such claims, but may actually arrest or detain those who attempt to seek asylum. A small number of governments, such as that of Australia, have a policy of mandatory detention of asylum seekers.

Non-governmental organizations concerned with refugees and asylum seekers have pointed out difficulties for displaced persons to seek asylum in industrialized countries. As their immigration policy often focusses on the fight of irregular migration and the strengthening of border controls it deters displaced persons from entering territory in which they could lodge an asylum claim. The lack of opportunities to legally access the asylum procedures can force asylum seekers to undertake often expansive and hazardous attempts at illegal entry.

Source : http://en.wikipedia.org