Gemara-

The Gemara , is a complex explanation of the Mishnah with many commentators. This was passed down to Moshe at Har Sinai along with: Mishnah, Zohar, and Torah(Wirtten). The Gemara is actually the base of Jewish law. It was getting forgotten along with Mishnah, and Zohar so they were written. The Mishnah by:Rav Yehudah HaNasi, and Rav Akiva. The Gemara by: Ravina, and Rav Ashi. In most(probably all) Gemarot, they are two side commentaries called:Rash"i, and Tosfot. In the Perek of Chezkat HaBatim, in Masechet Baba Batra Rash"i died, and the Rashba"m took over for his commentary. There are two Talmudim-Talmud Bavli(Babylonian), and Talmud Yerushlami(Jerusalem). The Gemara takes little parts of every Mishnah, and argues the whole thing out. They are split up into Masechtot, then into Perakim, then into Dapim. Masechta=Tractate. Perek=Chapter. Daf=Page.