The Apocrypha is a word that means ‘hidden’. Although not particularly accurate in this case, this is what several books are referred to that were written in the time between the Old Testament and New Testament eras (although one or two were likely written during or even after the NT was completed); it can also be referred to as the ‘OT Apocrypha’. There are 18 total books in the Apocrypha (as referred to by Protestants). They are: 1, 2, 3, and 4 Maccabees, 1 and 2 Esdras, Tobit, Judith, Letter of Jeremiah, Baruch, Additions to Esther (Greek), Prayer of Azariah and the Song of the Three Jews (in Daniel ch. 3), Susanna & Bel and the Dragon (chapters 13 & 14 of Daniel, respectively), Wisdom of Solomon, Wisdom of Ben-Sirach (a.k.a. Ecclesiasticus), Prayer of Manasseh, and Psalms 151.
I had heard of the Apocrypha for most of my life (my dad told me about it when I was little; I only knew just a little of it then). I had never read it until this past year; I recently finished, so I decided to post some about it. It took a while to finish reading, as I tended to stray away and back again over the year; it is actually about the same length as the NT, so it is not very long, relatively speaking. I decided to read it in the Good News Translation with Deutercanonicals / Apocrypha from the American Bible Society; this is a modern language version that I especially like. It is extremely straightforward and easy to read. For the meticulous student, however, there are other translations that might be more appealing (I will mention some that I know of later in this post).