The Gemara reference article from the English Wikipedia on 24-Apr-2004
(provided by Fixed Reference: snapshots of Wikipedia from wikipedia.org)

Gemara

For thoughtful child sponsors
The Gemara are the Rabbinical commentaries and analysis on the Mishnah, undertaken in the Academies of Palestine and Babylon over a 300 year period to about 500CE. The Mishnah is the core text, and the gemara is the analysis and commentary which “completes” the Talmud (from gamar (גמר), to complete). The Gemara, together with the Mishnah, makes up the Talmud. There are two Talmuds, corresponding to the Palestinian and Babylonian Gemara; both share the same Mishnah. See Talmud for more detailed discussion.

The Gemara, as redacted in the Talmud, is a record of the close analysis of the Mishna, over a 300 year period. This analysis is aimed at an exhaustive understanding of the Mishna’s full meaning. The analysis is essentially presented as a series of questions – with the Talmudic text as a record of each step in the process of reasoning and derivation. In the Gemara, every aspect of the Mishnaic text is treated as a subject of close investigation. (See [http://ohr.edu/judaism/articles/talmud.htm Talmudic Method, Harry Wolfson ])

The gemara is not strictly limited to an analysis of the Mishnah's text. It also brings in sources from the Mishnaic era, which were not included in the Mishnah compendium, which are called Tosefta (additions); the Talmud refers to these as beraitot, (the word for “outside”). The gemara also supplements the Mishna with haggadic (or aggadic) materials and biblical expositions, and is a source for history and legend.