Origins of Judaism
For centuries, the traditional understanding has been that Judaism came before Christianity and that Christianity separated from Judaism some time after the destruction of the Second Temple in 70 CE. Starting in the latter half of the 20th century, some scholars have begun to argue that the historical picture is quite a bit more complicated than that. In the 1st century, many Jewish sects existed in competition with each other, see Second Temple Judaism. The sects which eventually became Rabbinic Judaism and Early Christianity were but two of these. Some scholars have begun to propose a model which envisions a twin birth of Christianity and Judaism rather than a separation of the former from the latter. For example, Robert Goldenberg (2002) asserts that it is increasingly accepted among scholars that "at the end of the 1st century CE there were not yet two separate religions called "Judaism" and "Christianity"".
Daniel Boyarin (2002) proposes a revised understanding of the interactions between nascent Christianity and nascent Rabbinical Judaism in Late Antiquity which views the two religions as intensely and complexly intertwined throughout this period.
Orthodox Judaism
Orthodox Judaism may be categorized according to varying criteria. The most recognizable sub-group are the "Haredim" (literally, "anxious" or "fervent"), also known as Ultra-Orthodox, strictly Orthodox and the like. They form the conservative, strict and self-segregating part of the Orthodox spectrum. "Haredim" are characterized by a minimal engagement with modern society and culture if not their wholesale rejection, by avowed precedence given to religious values, and by a high degree of rabbinic authority and involvement in daily life. In spite of many differences, "Haredi" rabbis and communities generally recognize each other as such, and therefore accord respect and legitimacy between them. They also hold a lukewarm or negative assessment of more modernist Orthodox groups. "Haredim" are easily discerned by their mode of dress, often all black for men and modest by religious standards for women (including hair covering, long skirts, etc.)