Anti-Zionism is the non-recognition of a Jewish State. Anti-Zionists believe that Jews should leave Israel. It should not be completely confused with anti-Semitism, though the two often go hand in hand due to the fact that anti-Zionists frequently use anti-Semitic tropes.
Some ultra-religious Jews, such as the Neturei Karta sect, that praises Palestinian suicide bombers, are anti-Zionist. They believe that Jewish teaching says the Holy Land cannot be inherited until the Messiah comes.