Whether you refer to them as denominations, streams, movements or branches the American Jewish experience is as diverse as their interpretation of traditional Jewish law or halacha. Outside North America, the non-Orthodox streams of Judaism play a less significant role, and in Israel the vast majority of synagogues and other Jewish religious institutions are Orthodox, even though most Israeli Jews do not identify as Orthodox. Even within North America, the role of the movements has diminished somewhat in recent years, with growing numbers of American Jews and Jewish institutions identifying as “just Jewish.”
The largest affiliation of American Jews, some 35 percent of Jews identify as Reform. The movement emphasizes the primacy of the Jewish ethical tradition over the obligations of Jewish law. The movement has traditionally sought to adapt Jewish tradition to modern sensibilities and sees itself as politically progressive and social-justice oriented while emphasizing personal choice in matters of ritual observance.
Known as Masorti (traditional) Judaism outside of North America, Conservative Judaism sees Jewish law as obligatory, though in practice there is an enormous range of observance among Conservative Jews. The movement has historically represented a midpoint on the spectrum of observance between Orthodox and Reform, adopting certain innovations like driving to synagogue (but nowhere else) on Shabbat and gender-egalitarian prayer (in most Conservative synagogues), but maintaining the traditional line on other matters, like keeping kosher and intermarriage. About 18 percent of American Jews identify as Conservative.
Orthodox Jews are defined by their adherence to a traditional understanding of Jewish law as interpreted by rabbinic authorities over the centuries. Hallmarks of Orthodox religious life include strict observance of Shabbat (no driving, working, turning electricity on or off, or handling money) and of kosher laws. Though numerically the smallest of the big three — some 10 percent of American Jews identify as Orthodox. Unlike the Reform and Conservative movements, which have a recognized leadership that sets policy for movement-affiliated institutions, Orthodox Judaism is a looser category that can be further subdivided:
Modern Orthodox, also known as centrist Orthodoxy, this movement was an effort to harmonize traditional observance of Jewish law with secular modernity. Its ideal is summed up in the motto of its flagship institution, New York’s Yeshiva University: Torah Umadda (literally, Torah and secular knowledge).
Haredi or Ultra-Orthodox is typically marked by their distinctive black hats (for men) and modest attire (for women), Haredi Orthodox Jews are the most stringent in their commitment to Jewish law and tend to have the lowest levels of interaction with the wider non-Jewish society. One major exception is Hasidic Judaism’s Chabad-Lubavitch sect, which is known for its outreach to the wider Jewish community. Haredi Orthodox Jews, who are represented in the United States by Agudath Israel of America, can be further subdivided into two principal groups Hasidic and Yeshivish.
Hasidic Jews are heirs of the spiritual revivalist movement that began in Eastern Europe in the 18th century and, drawing on the Jewish mystical tradition, emphasized direct communion with the divine through ecstatic prayer and joy in worship. There are a number of distinct sects, most headed by a charismatic rabbi, or rebbe, including Chabad, Satmar, Ger and Skver.
Yeshivish, Sometimes also known as Litvish, these haredi Jews are heirs of the mitnagdim (literally “opponents”) who rejected the the rise of Hasidic Judaism in Europe. These Jews traditionally emphasized the intellectual aspects of Jewish life, particularly rigorous Talmud study for men. Yeshivish derives from the word yeshiva, or religious seminary.
Open Orthodox was founded in the 1990s by the New York Rabbi Avi Weiss. Its adherents, who consider the movement a reaction to a perceived shift to the right among the Modern Orthodox, generally support expanded roles for women in spiritual leadership and more openness to non-Orthodox Jews.
Following the thinking of its founder, Mordecai Kaplan, Reconstructionism holds that Judaism is the evolving civilization of the Jewish people. Its adherents hold varying opinions about the extent to which Jewish law, particularly the mitzvot, are obligatory. The movement is quite religiously progressive: Kaplan was the first American rabbi to preside over a public bat mitzvah celebration for his daughter, Judith, in 1922 and the movement’s rabbinical seminary was the first to accept openly gay students.
Sources : “Essential Judaism” Robinson, George. 2016. myjewishlearning.com. chabad.org