The third major grouping of the Hebrew scriptures—what we Christians call the Old Testament—is the Writings (Hebrew, Ketuvím, Greek Agiográfa). There’s some debate about whether they were considered part of the bible by Jesus’s day, since Jesus referred to the bible as “the Law and the Prophets” (Mt 7.12)—but He didn’t include “and Writings.” Some Christians insist that “and Writings” is implied, but honestly, that’s because we include the Writings. Jesus did consider the Writings to be scripture, because He quoted them (particularly Daniel and the Psalms). But not everyone in His day agreed on this; the Pharisees and Qumranis did, but the Saduccees and Samaritans didn’t.
The Writings consist of 11 books: Psalms, Proverbs, Job, Song of Songs, Ruth, Lamentations, Ecclesiastes, Esther, Daniel, Ezra-Nehemiah, and Chronicles. The Greeks split Ezra-Nehemiah and Chronicles in two when they translated them; and of course they resorted these books into the Old Testament by new categories: History (including Law), Poetry, and Prophets. So Ruth is tucked between Judges and Samuel, ’cause it’s historical; Daniel is tucked between Ezekiel and Hosea, ’cause it’s prophetic, sorta; and the poetry category was created for Job, Psalms, Proverbs, Ecclesiastes, and Song of Songs.
But while the Writings are found in our bibles in a sort of “chronological” order, they were actually written much later than the other books. They were compiled (in the case of Psalms or Lamentations), or written (in the case of Esther or Ruth), after the Jews had returned to Jerusalem from the Persian Empire, between the 400s and 100s BC. (That’s right, even Job was written at that time; lots of people believe it’s the oldest book in the bible, but its Late Biblical Hebrew vocabulary clearly makes it one of the latest books in the Old Testament.)
Five of the books—Song of Songs, Ruth, Lamentations, Ecclesiastes, and Esther—are specifically read during certain Jewish holidays. Song of Songs is read during Passover, since the rabbis like to interpret it as the love God has for Israel… even though it’s clearly about marital (and pretty physical, sometimes) love. Ruth is read during Weeks (Shavuót, which we call Pentecost), the festival of the harvest, since Ruth and Boaz hooked up during the harvest. Lamentations is read on the 9th of Av, the day the Romans destroyed the temple, which remembers that and pretty much every other horrible thing done to the Jews. Ecclesiastes is read during Tents (Sukkót), since its emphasis on change and the instability of life seems appropriate. And Esther is read during Lots (Purím) since, after all, Lots celebrates how Esther rescued the Jews of the Persian Empire.
That’s a brief introduction; Psalms next.