The Jews have famously lacked a homeland since the Romans threw them out of Palestine and it was only in the 19th century that a movement to return to Israel go moving. The religious Jews were dead against the idea as the Torah promised that they would only go back when the Messiah came. The Holocaust came first though and suddenly the idea of a Jewish homeland became attractive to many parties (except, of course, the Arabs living there).
Israel today has around 6 million inhabitants but 1 million of those are Arabs and another 1 million are Russians, and no one has any idea how many of them are really Jewish or just pretending( it was easy enough in Russia after the Wall fell down to buy papers proving you were an ancient Sumerian, if you wanted, never mind Jewish). Although it has to be said there are plenty of Born Again Jews in modern Israel.
Around the rest of the world there are another 7 million Jews living just about everywhere imaginable. Throughout history Jews assimilated into their host countries, absorbing the language and customs. Not all swallow the pill that they should up and leave in favour of a Biblical homeland.
All Jews around the world have the right of return though: aliyah. They can turn up, ask to be Israeli and the government will give them some cash, Hebrew schooling and training in the art of loud, pointless argument… okay, we made the last part up but it could have been true.