The Gospels and epistles of Paul were recognized as authoritative when they were written. Various lists, few as they are, have different collections of books.
- Eusebius (AD 300) include 4 Gospels, Acts, 13 epistles, 1 Peter, 1 Jn., Rev.
- Codex Vaticanus (300): 39 OT books, Apocrypha, 22 books of the NT (missing 1 & 2 Tim., Titus, Philemon, and Rev.)
- Codex Sinaiticus (330): OT segments, 7 apocryphal books, the 27 books of the NT as we have them today, the Epistle of Barnabas, and the Shepherd, by Hermas
- Athanasius (367): the 27 books as we have them today. Africanus and Melito of Sardis also opposed the inclusion of the Apocryphal books.
- Jerome's Vulgate (382): The 66 books of the Bible as we have them today
- Council of Rome (382): The 39 books of the OT, the books of the Apocrypha and the 27 books of the NT. The Synod of Rome added the books to the Vulgate over Jerome’s objections.
- Council of Hippo (393): The 27 books of the NT as we have them today plus 6 books of the Apocrypha
And so on. The Gospels and letters of Paul were never in dispute. Some of the General Epistles were occasionally in dispute. The books of the Apocrypha have always been disputed.
> Who composed it?
I believe the NT was composed by Matthew, Mark, Luke, John, Paul, Peter, James, Jude, and an anonymous writer (Hebrews).
> What is the difference in the catholic Bible and the KJV of the Bible?
When the KJV was published in 1611, there was no difference. The KJV included the books of the Apocrypha as a placating nod to the pope, but those books were removed in the late 19th century.