The 1951 Geneva Convention is the main international instrument of refugee law. The Convention clearly spells out who a refugee is and the kind of legal protection, other assistance and social rights he or she should receive from the countries who have signed the document. The Convention also defines a refugee’s obligations to host governments and certain categories or people, such as war criminals, who do not qualify for refugee status. The Convention was limited to protecting mainly European refugees in the aftermath of World War II, but another document, the 1967 Protocol, expanded the scope of the Convention as the problem of displacement spread around the world.

Source: http://www.unrefugees.org/site/c.lfIQKSOwFqG/b.4950731/k.A894/What_is_a_refugee.htm