Several groups, sometimes called "denominations", "branches," or "movements", have developed among Jews of the modern era, especially Ashkenazi Jews living in anglophone countries. Despite the efforts of several of these movements to expand their membership in Israel and achieve official recognition by the Israeli government, non-Orthodox movements have remained largely a feature of Judaism in the diaspora.
Historically, the division of Jews in many Western countries into denominations, which in the United States in particular took the form of three large groups known as Orthodox, Conservative and Reform, can be traced to Jewish reaction to the Haskalah (Jewish Enlightenment) and its aftermath, and to a certain extent the philosophies of these movements were shaped in reaction to one another. Several smaller movements have emerged in the years since. In more recent years, all of these movements have been shaped by the challenge of assimilation.
The movements differ in their views on various religious issues. These issues include the level of observance, the methodology for interpreting and understanding Jewish Law, biblical authorship, textual criticism, and the nature or role of the the Messiah (or Messianic age). Across these movements, there are marked differences in liturgy, especially in the language in which services are conducted, with the more traditional movements emphasizing Hebrew. The sharpest theological division occurs between Orthodox and non-Orthodox Jews who adhere to other denominations, such that the non-Orthodox movements are sometimes referred to collectively as the "liberal denominations" or "progressive streams."
Until recently most Jews rejected the term denomination as a label for different groups and ideologies within Judaism, arguing that the notion of denomination has a specifically Christian resonance that does not translate easily into the Jewish context. However, in recent years the American Jewish Year Book has adopted "denomination," as have many scholars and theologians.[1] Other commonly used terms are movements, branches, trends, streams, or even flavors of Judaism. This article uses the terms interchangeably, without purporting to affirm the validity of one term over another.
The Jewish denominations themselves reject characterization as sects. Sects are traditionally defined as religious subgroups that have broken off from the main body, and this separation usually becomes irreparable over time. Within Judaism, individuals and families often switch affiliation, and individuals are free to marry one another, although the major denominations disagree on who is a Jew. It is not unusual for clergy and Jewish educators trained in one of the liberal denominations to serve in another, and left with no choice, many small Jewish communities combine elements of several movements to achieve a viable level of membership.