Karaites accept the written Torah and reject the rabbinic oral law entirely — no Talmud, no Mishnah, no rabbinic authority. The movement emerged in eighth-century Baghdad and at its height may have been a significant fraction of world Jewry. The practical differences are substantial: no tefillin as the rabbis define them, different Sabbath rules, a different calendar, and different holiday dates, which means a Karaite and a rabbinic Jew often keep Passover in different weeks.