The Talmud is a collection of Jewish law and teachings. The core of the Talmud is the Mishnah, a compilation of laws and rulings collated by Rabbi Judah the Prince about 200 A.D. The early teachers of the Mishnah were known as tannaim. The Gemara is a commentary on the Mishnah produced by scholar-teachers known as amoraim in the years 200–500 A.D. The Mishnah and the Gemara together comprise the Talmud (although sometimes the Gemara alone is referred to as Talmud). The Talmud has come to us in two basic versions: the Palestinian or Jerusalem Talmud compiled around 400 A.D. and the Babylonian Talmud compiled around 500 A.D. It is the latter which is considered most authoritative and is most widely used in Jewish education today.