The United Nations Relief and Works Agency (UNRWA) defines a Palestine refugee as a person "whose normal place of residence was Palestine between June 1946 and May 1948, who lost both their homes and means of livelihood as a result of the 1948 Arab-Israeli conflict". The descendants of the original Palestine refugees in the male line "are also eligible for registration."
UNRWA aids all "those living in its area of operations who meet this definition, who are registered with the Agency and who need assistance" and those who first became refugees as a result of the Six-Day War, regardless whether they reside in areas designated as Palestine refugee camps or in other permanent communities. A Palestine refugee camp is "a plot of land placed at the disposal of UNRWA by the host government to accommodate Palestine refugees and to set up facilities to cater to their needs". Today, 58 UNRWA recognised refugee camps in Jordan, Lebanon, the Syrian Arab Republic, the Gaza Strip and the West Bank habor only "one-third of the registered Palestine refugees, more than 1.4 million." The UNRWA definition does not cover final status. In many cases UNHCR provides support for the children of Palestine refugees too.
Registered descendants of UNRWA Palestine refugees are, like “Nansen Passport” and “Certificate of Eligibility” holders (the documents issued those displaced by World War II) and UNHCR refugees  are inherited the same UNRWA Palestine refugee status as their male parent.
Based on the UNRWA definition, the number of original Palestine refugees has declined from 711,000 in 1950 to an estimated 30 to 50,000 in 2012. An estimated 5 million Palestine refugees are registered in total in 2012.
In 2012 the number of registered descendants of male parents of the original Palestine refugees, based on the UNRWA registration requirements, are an estimated 4,950,000.