These books are further grouped into three sets. The first set is called the Torah, or the five books of Moses. Properly speaking, therefore, the Torah is not the same as the Old Testament. The Torah is merely one part of the Old Testament.
The word ‘Torah’ is often (mis)translated into English as ‘law,’ but ‘instructions’ or ‘directions’ might be more accurate. These five books are also called the ‘Pentateuch.’
The second segment of the Tanakh is called the ‘prophets’ or Nevi’m (also transliterated as Nebiim). This group is subdivided into the ‘earlier prophets’ (Joshua, Judges, Samuel, and Kings), and the ‘later prophets’ (Isaiah, Jeremiah, Ezekiel, and the twelve ‘minor’ prophets).
The third segment is the Ketubim (also Ketuvim) or ‘writings.’ This group includes Psalms, Proverbs, Job, Ruth, Esther, Song of Solomon, Lamentations, Ecclesiastes, Daniel, Ezra, and Chronicles.
The order of the books in the Hebrew Bible varies: in the Tanakh the books are presented in the three groups described above. Most English translations of the Old Testament follow a different order, a pattern first found in the Septuagint, a translation of the Hebrew Bible into Greek, made by the Jewish communities in Egypt sometime between 300 BC and 100 BC.
Franz Delitzsch and Johann Friedrich Karl Keil coauthored an exhaustive analysis of the Tanakh. They write:
The prophetic histories are followed in the Old Testament canon by the prophetic books of prediction. The two together form the middle portion of the threefold canon.
Delitzsch and Keil note that definition of the words ‘prophet’ and ‘prophecy’ need to be examined. The middle third of the Tanakh is called the ‘prophets,’ but isn’t Moses a prophet, too? Yet he and his words are recorded in the first third. Arguably, some texts in the final third are also prophetic.
The Torah is indeed also a prophetic work, since Moses, the mediator through whom the law was revealed, was for that very reason a prophet without an equal (Deu. 34:10); and even the final codification of the great historical law-book possessed a prophetic character (Ezr. 9:11). But it would not have been right to include the Torah (Pentateuch) in that portion of the canon which is designated as “the prophets” (Nebiim), inasmuch as, although similar in character, it is not similar in rank to the other prophetic books. It stands by itself as perfectly unique — the original record which regulated on all sides the being and life of Israel as the chosen nation, and to which all other prophecy in Israel stood in a derivative relation. And this applies not to prophecy alone, but to all the later writings. The Torah was not only the type of the prophetic histories, but of the non-prophetic, the priestly, political, and popular histories also. The former followed the Jehovistic or Deuteronomic type, and the latter the Elohistic. The Torah unites the prophetic and (so to speak) hagiographical styles of historical composition in a manner which is peculiar to itself.
Comparing the groupings and orderings found in the Hebrew Tankah with those found in the English Old Testament is a worthwhile and thought-provoking task.