There is no single Bible: 24, 39 or 46 books, depending who asks
Jews count 24 books in the Tanakh. Protestants split the same material into 39 for their Old Testament, while Catholics include 46, adding texts they call deuterocanonical. The Samaritans accept only the five books of the Torah, in a version saying Moses received the Commandments on Mount Gerizim rather than Sinai.
Canon comes from the Greek kanōn, a rule or measuring stick, and since the 14th century English has used it for the list of books a church accepts as inspired. Each community settled its own list through argument and agreement. The Hebrew Bible has three parts: five books of Torah, eight of Prophets and eleven of Writings, mostly in Hebrew with some Aramaic. The Greek Septuagint, broadly similar but with extra texts, serves as the Old Testament in some Christian liturgies. The New Testament almost always has 27 books.
When the Jewish canon closed is contested. The evidence points somewhere between 200 BC and 200 AD. A popular scheme dates the Torah to about 400 BC, the Prophets to about 200 BC and the Writings to around 100 AD, perhaps at a Council of Jamnia, but modern scholars increasingly doubt that council ever made such a decision. Later tradition credits collecting efforts to Nehemiah, Ezra and Judas Maccabeus, and some argue the Hasmonean rulers fixed the list.
The Samaritans emerged as a distinct people after Assyria conquered Samaria in 722 BC. Their Pentateuch differs from the standard Hebrew text in small matters like ages in genealogies and larger ones, including a monogamy commandment and the insistence that sacrifice belongs on Gerizim, not in Jerusalem. The community at Nablus says it holds the oldest Torah scroll, written by Abisha, a grandson of Aaron. Scholars still consult their version to reconstruct the original text.
Christian lists hardened slowly. Regional councils at Rome in 382, Hippo in 393 and Carthage endorsed collections, but only the Council of Trent, running from 1545 to 1563, formally fixed the Catholic 73-book canon. The Church of England settled its list with the Thirty-Nine Articles in 1563 and the Orthodox with the Synod of Jerusalem in 1672. Theologian William J. Abraham argues that what ultimately decided inclusion was which books congregations were already reading in worship.
Source: Biblical canon
