Orthodox Judaism is an internally diverse denomination of Judaism that generally tends toward a strict interpretation of halakha—Jewish law. There are two main streams within Orthodox Judaism: Modern Orthodox Judaism and Haredi (sometimes called “Ultra-Orthodox”) Judaism. Modern Orthodoxy advocates fidelity to halakha along with a willingness to engage in the modern world. Haredi Judaism, on the other hand, prefers not to interact with secular society, seeking to preserve halakha without amending it to modern circumstances and to safeguard believers from involvement in a society that challenges their ability to abide by halakha. Orthodox Judaism claims to preserve Jewish law and tradition from the time of Moses. Widespread anti-Semitism prevented Jews from engaging in the wider societies in which they were living until the eighteenth and nineteenth centuries, when they began enjoying greater rights and freedoms. The resulting Jewish integration into non-Jewish societies led to the formulation of a distinct Orthodox identity that eschewed such integration to varying degrees.
Orthodox Judaism, taken as a whole, is arguably the most powerful force in Jewish affairs worldwide. The political and spiritual sectors of Israel are largely controlled by Orthodoxy’s two divisions, Modern Orthodoxy and Haredi Judaism, respectively. Modern Orthodox Judaism is generally coterminous with Zionism, the political advocacy of Jewish national sovereignty. Modern Orthodox Jews were a driving force behind the creation of the state of Israel and are now present throughout Israeli politics and international pro-Israel organizations. Conversely, most Haredi Jews reject Zionism, focusing their life on the Jewish religion and exerting pressure on Israeli religious authorities to abide by strictly Orthodox interpretations of halakha.