Judaism
Around the 1st century CE, there were several small Jewish sects: the Pharisees, Sadducees, Zealots, Essenes, and Christians. After the destruction of the Second Temple in 70 CE, these sects vanished. Christianity survived, but by breaking with Judaism and becoming a separate religion; the Pharisees survived but in the form of Rabbinic Judaism (today, known simply as "Judaism"). The Sadducees rejected the divine inspiration of the Prophets and the Writings, relying only on the Torah as divinely inspired. Consequently, a number of other core tenets of the Pharisees' belief system (which became the basis for modern Judaism), were also dismissed by the Sadducees. (The Samaritans practiced a similar religion, which is traditionally considered separate from Judaism.)
Modern Orthodox Judaism
Nevertheless, the two movements are philosophically distinct on two broad counts.Applying the above distinction, in Israel today, Modern Orthodoxy - as distinct from (right-wing) Religious Zionism - is represented by only a select group of institutions: the Religious Kibbutz Movement, Neemanei Torah V'Avoda, the Meimad political party, and the Shalom Hartman Institute, Yeshivat Har Etzion / Migdal Oz and Yeshivat Hamivtar/Ohr Torah Stone Institutions/Midreshet Lindenbaum (some would include Yeshivat Hesder Petach Tikva, Yeshivat Ma'ale Gilboa, and the Tzohar Foundation).