The books that are found in the Bible were selected on account of their divine inspiration. These texts have become a governing guide for the Jewish people. Nevertheless, there are numerous other texts that never made it into the Bible, many of which are lost today. This choosing of texts for the Bible is referred to as canonization, a method of measuring a text’s importance. Canonization is the long procedure of collecting and sequencing of the texts in an order of authority and importance.
The Pentateuch (Torah), as we know it today, was completed during the Babylonian exile, by the time of Ezra. The Neviim (Prophets) were finalized during the Persian era, approximately 323 B.C.E. The conclusion of the last section of the Bible, ketuvim (Writings) is debated; however, a majority of scholars believe its final canonization occurred in the second century C.E.
The canon of the Hebrew Bible is somewhat different than that of the Greek Bible (which is the basis for the Christian Bible). The Greek Bible includes several additional books, which were not accepted into the Hebrew Bible. These texts include – 1-4 Maccabees, Judith, and Psalms of Solomon. Furthermore, the two Bibles differ in their sequence of the texts and writings, as well as the order of importance in the placement of texts.
Sources: Eisenberg, Ronald L. The JPS Guide to Jewish Traditions. PA: Jewish Publication Society, 2004; Wigoder, Geoffrey , Ed. The New Standard Jewish Encyclopedia. NY: Facts on File, 1992; "Creating the Canon".