So what it’s true.
In recent history the area called Palestine includes the territories of present day Israel and Jordan (see map above. For earlier history of the term see article). From 1517 to 1917 most of this area remained under the rule of the Ottoman Empire.
Ottoman Empire was dissolved at the end of World War I. Its successor, modern republic of Turkey, transferred Palestine to British Empire control under the Lausanne agreement that followed WW I.
In 1917 Great Britain issued the Balfour Declaration for “the establishment in Palestine of a national home for the Jewish people”. In 1922 Britain allocated nearly 80% of Palestine to Transjordan. Thus, Jordan covers the majority of the land of Palestine under British Mandate. Jordan also includes the majority of the Arabs who lived there. In other words, Jordan is the Arab portion of Palestine.
The residents of Palestine are called “Palestinians”. Since Palestine includes both modern day Israel and Jordan both Arab and Jewish residents of this area were referred to as “Palestinians”.
It was only after the Jews re-inhabited their historic homeland of Judea and Samaria, that the myth of an Arab Palestinian nation was created and marketed worldwide. Jews come from Judea, not Palestinians. There is no language known as Palestinian, or any Palestinian culture distinct from that of all the Arabs in the area. There has never been a land known as Palestine governed by Palestinians. “Palestinians” are Arabs indistinguishable from Arabs throughout the Middle East. The great majority of Arabs in greater Palestine and Israel share the same culture, language and religion.
http://www.science.co.il/History-Palestine.asp
“So what it’s true.”
Beyond what you’ve written, which is all true, the “Palestinian Arabs” are the Arabs that none of the other Arab countries want and further, they have become a “convenient foil” for the Arab World to screw with Israel. The Palestinians have allowed themselves to believe that they have been disenfranchised from “Palestine” and the rest of the Arabs have fed that notion to help to try and defeat Israel. The truth of the matter is that the Arab World regards the Palestinians as worthless crap that they don’t want to care for.