When was it put down in writing?
Thank you for your question:
The Bible consists of Two Testaments.
The Old Testament was written in Hebrew and Aramaic by various authors over a long period of time and covers history from the beginning (Genesis 1:1) c.4000 BC until about 450 BC (the prophet Malachi).
The Hebrew word 'torah' which means 'teaching (of the law)', was sometimes used to designate the whole collection of books, but more correctly referred to the first major section called the Pentateuch (the first five books: Genesis, Exodus, Leviticus, Numbers, and Deuteronomy.) The next section was called 'The Prophets', which was subdivided into the Former Prophets (i.e. Joshua, Judges, Samuel, and Kings), and the Latter Prophets (Isaiah, Jeremiah, Ezekiel, and the 12 (Minor Prophets)). The final section is 'the Writings', and consists of Psalms, Proverbs, Job, and Song of Solomon, Ruth, Lamentations, Ecclesiastes, Esther, Daniel, Chronicles, Ezra and Nehemiah. This order is different from our modern Old Testaments, but reflects the typically used order of the time based on importance.
All were accepted and considered authoritative by the Jews from the time of their writing, and were passed down as such.
The translation of the Hebrew Bible (the Old Testament) into Koine Greek was completed around 180BC and is known as the Septuagint. This contains all the books that appear in the Old Testament in our Bibles today and shows that the books of the Hebrew Bible were agreed upon by that time. Officially, the Hebrew canon was closed at the Council of Jamnia c. AD 90.
The Septuagint contains extra books that the Hebrew version of the Old Testament (known as the Masoretic text) does not. These are called the apocrypha. The apocrypha are books that the Jews do not accept as Scripture, but view as historically important.
The New Testament was written in Koine Greek by various authors after c. AD 45 and before c. AD 100. Its 27 books were formalised into a single volume within the next two and a half centuries. The New Testament canon as it is exists today was listed by Athanasius, Bishop of Alexandria, in c. AD 367.
I hope this helps.