How did the Mishna and Gemara become the two main parts of the Talmud?

The Talmud is composed of two primary parts: the Mishna and the Gemara. Their integration into a single work occurred through a historical process of codification and subsequent scholarly interpretation.1234

• The Mishna: Compiled and given final form by Judah ha-Nasi in the early 3rd century CE, the Mishna serves as a comprehensive, authoritative collection of Jewish oral laws that supplement the scriptural laws of the Torah.31
• The Gemara: Following the completion of the Mishna, generations of scholars known as amoraim ("interpreters") in Palestine and Babylonia engaged in intensive study of the text. Their collective explanations, debates, and legal decisions regarding the Mishna were gathered into collections called the Gemara.341

In the final structure of the Talmud, the Mishna and Gemara are presented in juxtaposition, with the Gemara functioning as a running commentary and elaboration on the Mishnaic text. This dialectic style reflects the tradition of the Talmudic academies, where scholars sought to exhaust the meaning of the law through rigorous analysis.1254