You are confused. The name 'Palestine' dates back to biblical days. It was the official name for the area up until the crusades. The name was used unofficially until the fall of the Ottoman empire, when it became known again as Palestine. Why reference the West Bank, Palestinians lived throughout Palestine. Some Israelis would like to believe they settled a largely deserted area. Would that have been true, there would be much less violence and strife in the world. It's a complicated history of what happened once the Ottoman Empire collapsed and Britain began to administer the area. Jews were brought into the area to have a homeland. The original conception was that Arabs and Jews would live in harmony. The Arabs weren't thrilled with this arrangement. There are a number of myths that have been created by both sides. Whatever the facts, hundreds of thousands of Palestinians were forcefully expelled/left voluntarily (depending upon whose version you accept). Israel will not let these people or their descendants return, saying that they must settle in Arab lands. Though the Palestinians outnumbered the Israelis, they had a smaller, less modern army, and lacked the financial resources of the Israelis. They were no match for the Israelis. After the U.N. partitioned Palestine into Jewish and Arab sections, Israel then proceeded to annex a third of the Arab land by conquest.
I don't know who did what or how. I'm not sure how anyone determines the truth today. I say it's irrelevant. Something has to be done to give the Palestinians right to determination. Israel's position, seems to be that they conquered and politicked their way to the land, and now the Palestinians should just deal with it. The Palestinians seem to feel that they should take their land back the same way the Israelis took it. Lacking an effective military, they are using poor man's weapons, terrorism. It is of course hard for us to work up much sympathy for terrorists. The Palestinians complain that if they dropped terrorism, everyone would just forget about them. I suspect there is some truth to that, but still feel that terrorism against innocent civilians is counter productive.
I do know that if a lasting peace could be achieved, all of the middle eastern people could live richer, more satisfying lives. Israel wouldn't have to continue to spend huge sums on the military, the U.S. could stop subsidizing Israel (no country removes more aid per capita), and free trade between Israel and it's Arab neigbors would benefit all.