includes rabbinic works that were written from about 10-220 C.E.
The Amoraic period went from about 219 C.E. to about 500 C.E. The sages in this period expounded on the Mishnah. Eventually, their work was compiled as the Gemara. The Mishnah and the Gemara together make up the Talmud. The geonim were the heads of two Talmud academies in Babylonia (in Sura and Pumbedita) from the late 500's until the early 11th century. It was their role to teach and interpret the Talmud and to formulate legal decisions based on the Talmud.
Rishonim (coming from the root "rishon" meaning first or elders) is a term for the leading Rabbis who lived approximately during the 11th to 15th centuries, in the era before the writing of the Shulhan Arukh and following the Geonim. The name "Rishonim" is a designation found in the Talmud and applied to authorities who (appropriately) lived before the one who quotes them. The title is generally used to mean "predecessor" or "ancestor" and to imbue a sense of authority to the text. Among the most famous of the Rishonim are Rashi, Maimonides, and Nachmanides.
Aharonim (lit. "later ones") is a term for the leading Rabbis who lived from roughly the 16th century to the present. Aharonim is a technical term used in later rabbinical literature generally to indicate authorities who are contemporaries of the person quoting them or who belong to the generation immediately preceding him. It is especially applied to the rabbinical authors following the age of the Shulhan Arukh � the end of the sixteenth century. Thus the publication of the Shulhan Arukh marks the transition from the era of Rishonim to that of Acharonim.
Since Jewish laws are found in several places (Torah, Talmud, Tosefta, etc.) early rabbis and scholars tried to compile the various laws together in one source. These works include the Mishneh Torah, Shulhan Arukh, and the Tur.
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