Orthodox Judaism is the branch of Judaism that has the strictest adherence to traditional Jewish practices and beliefs. It originated in response to the innovations in Jewish practice introduced by the Reform movement. Orthodox Judaism claims that both the Torah (the first five books of the Hebrew Bible) and the Oral Torah (the interpretive Talmud) are authoritative and fixed regarding Jewish doctrine and observance, thus requiring modern Orthodox Jews to uphold ancient Jewish law. God's divine revelation given to Moses on Mount Sinai was both supernatural and eternal, thus, Jews are strictly required to obey this revelation. This stance is a rejection of the positions held by both Conservative and Reform Judaism, which use more flexibility in interpreting Jewish law in the modern times. Orthodox Judaism's religious observances include daily worship, traditional prayers, study of the Torah, dietary laws, and gender segregation in the synagogue. The Hebrew language is essential in Orthodox religious practices. Orthodox Jews are also strict in their observance of the Sabbath. In spite of the doctrinal and ritual strictness of Orthodox Judaism, different Orthodox sects have arisen over the centuries. One distinction within the Orthodox is in regard to social engagement. Some sects of Orthodox Judaism claim the Jews, as the people of God, should live completely segregated from gentiles whereas other Orthodox sects believe Jews can keep the Torah and live in the secular world simultaneously. Most Orthodox Jews adhere to a traditional style of clothing with strict guidelines.