A baraitha is an "external" piece of Jewish oral law, usually from the same era as the Mishnah and often by the same sages. When Rabbi Judah haNasi compiled the Mishnah, he left out lots of material which could not be included in the 63-volume work for sake of brevity. Some of this found its way into the Tosefta and the Talmud. In the latter it is usually marked by the Aramaic word Tanya, "It was orally taught," or Tanu Rabanan, "Our Rabbis have orally taught," as opposed to Tnan, "We have orally taught" which relates to Mishnah paragraphs.

The legal status of baraithot is basically similar to that of the Mishnaic text, but it is scrutinised more closely by the Talmud, and often anonymous baraithot are attributed to particular Tannaim.

The style of baraithot is basically indistinguishable from that of the Mishna, but some come closer to Mishnaic idiom than others. The minor tractates of the Talmud are examples of post-Mishnaic texts that can deviate slightly in style. Nevertheless, the second chapter of Kallah Rabbathi is often appended to the five-chapter tractate of Avoth, at it is similar in style and content.