What Was the Difference Between the Septuagint and the Vulgate?

I apologize if there was any confusion. The discrepancy is due to the differences in biblical canons among various Christian traditions. The Septuagint, a Greek version of the Jewish Scriptures, actually contained a more extensive list of books than we would find in a typical Protestant Old Testament today. The Septuagint does indeed include 46 books that the Catholic church eventually defined as the canon of their Old Testament. Coupled with the 27 books in the New Testament, this does total 73 books. However, later on, the Protestant Reformation led by Martin Luther in the 16th century rejected some of these books, considering only 39 Old Testament books and 27 New Testament books as canonical, leading to a total of 66 books in most Protestant Bibles today. So, the number of books in the "first Christian Bible" could be either 73 or 66, depending on whether one is referring to the early Christian usage (which would become the Catholic Canon), or the later Protestant Canon. I hope this clarifies the confusion.