Apocrypha refers, in popular usage, to any texts of disputed inspiration or authenticity. Within Christianity, "the Apocrypha" usually refers specifically to 14 books included in the Septuagint (the first Greek language Tanakh - used by Hellenistic Jews) but absent from the Hebrew Masoretic Text.
These books are:
- 3 Esdras
- 4 Esdras
- Rest of Esther
- Prayer of Manasses
- 1 Maccabees
- 2 Maccabees
- Song of the Three Children
- Story of Susanna
- The Idol Bel and the Dragon
There are other "extra" Septuagint books included in the Bibles of Eastern churches, such as the Book of Enoch, the Book of Jubilees, and 3 and 4 Maccabees.
Since the Council of Trent, most of these books have been accepted as canonical by the Roman Catholic Church (but not 3 or 4 Esdras). The last three of these books are included in Catholic Bibles as part of the Book of Daniel, and the Rest of Esther is included as part of the Book of Esther. Catholics prefer the term deuterocanonical, derived from Greek for "second Canon". In this terminology, "protocanon" refers to those books which were never disputed in the Church, "deuterocanon" those books which were disputed initially but which (Catholics believe) the Church later decided to adopt. Catholics then reserve the term "Apocrypha" for what Protestants call "Psuedipigrapha".
All of the "extra" Septuagint books (those in the Septuagint but not the Masoretic Text) are excluded from the Tanakh, and their canonicity has been rejected by Judaism. Protestant churches generally adhere to the Hebrew Tanakh as the Christian Old Testament, and thus also reject the canonicity of Apocryphal books. However, the Apocrypha are generally considered to be useful and rewarding to study, and some of the Anglican Communion editions of the Bible include some apocryphal books.
For the Old Testament, the term Apocrypha is usually restricted by Protestants to refer only to those books which are accepted by Catholics or Eastern Orthodox, while the term Pseudepigrapha is used to refer to those books ancient works in a biblical style but never had the same acceptance that the Apocrypha had. By contrast, Catholic usage is to call these books Apocrypha. For the New Testament, the two terms are equivalent, since there exists among Christians a consensus on the canon of the New Testament which is missing for that of the Old.