The Talmud is a commentary on the Mishna (the oral law) written in Babylonia containing discourses of Amoraim spanning the 3th-5th century
The Talmud Bavli was written by Ravina and Rav Ashi in Babylonia. It consists of over 5000 pages and has had many, many commentaries written on it. The most prevalent are: rashi, tosafot, rif-rabbi-isaac-alfasi,rambam, ramban, rashba, rabbeinu-asher, ritva and maharsha. Rashi is universally accepted as the simple explanation. This Talmud is the basis for all Jewish Halacha - law today.
Here are the Bavli Masechtos (Tractates), see mishna for full list:
Zra'im (Seeds)
maseches-brachos
Mo'ed (Holiday)
maseches-shabbosmasechet-eiruvinmaseches-pesachimtractate-beitzamaseches-rosh-hashanamaseches-yomamaseches-sukkahmasechet-taanismaseches-megillahmasechet-moed-katantractate-chagiga
Nashim (Women)
masechet-yevamotmaseches-kesubosmaseches-nedarimmaseches-nazirtractate-sotahmaseches-gitinmaseches-kiddushin
Nezikin (damages)
bava-kammabava-metziabava-batramaseches-sanhedrinmaseches-makkosmasechet-shevuotmasecheth-avodah-zarahmaseches-horayos
Kodshim (consecrated things)
maseches-zevachimmaseches-menachoschulin-tractatemaseches-bechorosarachin-tractatemaseches-temuramaseches-krisusmaseches-meilamaseches-tamid
Taharot (Ritual purity)
maseches-niddah
