The Catholic canon (or list of books) contains 46 Old Testament books, which is 7 more than those accepted by many other Christians. These books are known as the Deuterocanonical books (or 2nd canon). They are also referred to as 'apocrypha' which means 'hidden'.
These books are Tobit, Judith, Baruch, Ecclesiasticus (or Sirach), Wisdom, 1 Maccabees, 2 Maccabees, as well as additional sections to the books of Esther and Daniel.
The number of books in the New Testament is 27, which is the same in all Bibles.
Bibles will indicate whether Deuterocanonical / apocrypha books are included, or will simply say "Catholic edition" or "Catholic Bible".