Johnny and TIS: Judaism is a religion, and a practitioner is Jewish, just as Catholicism is a religion and a practitioner is Catholic. What you might see in America as "Jewish culture" or "Jewish food" is associated with Jews of Eastern European extraction. But they are far from the only ethnic group who are Jewish.

Here's an analogy: much of what non-Catholic people in America popularly associate with "Catholic" or "Catholic culture" is associated with Irish Catholics, mainly because the Irish were the first large Catholic immigrant group in America. The St. Patrick's Day parade, eating cod and boiled potatoes, being involved in local politics, going to Catholic schools--these are things that many people think of as "Catholic" when in fact the impression was mostly made by Irish Catholics (not Italian and Polish Catholics, who are much more numerous). When people think of Islam, they thing of Arabs and their culture and background: desert, camels, tents, checked headdresses for men, etc. In fact, there are far more ethnic Asian and Pacific Islanders who are Muslims than Arabs. Indonesia has the largest Muslim population in the world, followed by Pakistan. Neither is an Arab country.