Not exactly. The Romans named the province "Palestine" some 2000-odd years ago after one of the Jewish anti-Rome rebellions, mostly just to "punish" the Hebrews for the revolt by naming the province after their biblical enemy.
The people who identify as Palestinians today are mostly descendants of 'fairly recent' immigrants to the land, just like most of the Jews are. Just go back say 100-150 years, the land was basically barren. The Ottomans ruled it. Jews trickled in as Europe grew more hostile to them. The Jewish immigrants improved the land. That increased the absorptive capacity of the land, so Arabs came in too. Then after WW1, Britain took control of the former Ottoman empire and promised a small strip for a Jewish homeland. More Jews came, this time with more skills learned in Europe about irrigation and crop growing, so they irrigated and increased the absorptive capacity even further. More Arabs came. The Arabs and Jews clashed a lot between WW1 and WW2. Then WW2 ended and the Jews that survived Europe felt they could no longer trust their neighbors who didn't protect them, and moved. More clashes, and the Jews and Arabs both clashed with the British. By 1948 the Jews organized under one umbrella (after some infighting including attacks by their own groups) and declared indepedence. The Arabs on the other hand were not organized and tried to hide behind their brethren in Syria, Jordan, Egypt etc (which is where they or their close ancestors came from in the first place) who promised to kick the Jews out. There are some contemporaneous reports that the Arab states (all created by the British, with a token given to France) warned the Arabs to leave the territory to make way for the Arab Armies that were invading. So many left. But, the Arabs lost. And they lost several more times. The displaced Arabs are in Jordan, and Lebanon, and the West Bank and Gaza. But not all. Some are Israeli, and some are Israel "green card" holders who refuse citizenship but reside there. But to say it is "Palestinian" land is a misnomer. The Palestinians named themselves after the name the Romans gave the territory which was ruled at the time by Jews.
Bottom line is, there were always some people living there, mostly in Jerusalem and in the more fertile northern and western areas. They were Arab and Jew under Ottoman rule, then British rule. The population growth from 1848 to 1948 was exponential including both Arab and Jew.
After 1948, somewhere between 500k-1MM Jews that were living in Arab lands for 2000 years fled and moved into Israel out of fear. Then after the Cold War another 500k-1MM Soviet Union Jews moved in.
For the most part, they are all "colonizers" if you want to think in those terms but really the Jews were mostly refugees and the Arabs were mostly immigrants who came to capitalize on the improvements made in that period of time. And they "colonized" basically barren land, and improved it. But the Arabs didn't accept any partition of the land for a Jewish homeland, and here we are today.
The idea that Palestinians are literal descendants of Philistines or any other ancient tribe is false. They are as newly arrived as the Jews, only without any sense of order in how to create their own homeland in where they reside. In their minds they are still stuck in 1948.
The Jewish population increased much faster than the Muslim (or Christian) population. Most of the growth in the Arab population can be accounted for by natural population growth, rather than by immigration.
Thanks for that summary.