What is the origin of the Catholic apocrypha? In the Catholic tradition, several "apocryphal" books are used in addition to the same Old Testament canon used by Protestants.


What is the origin of these books and how do they differ from from the other books?  
Do Catholics view them as infallible?  
Are they considered to be on the same level with the rest of the Old Testament or do they have some second rate status such as some form of non-divine wisdom literature?
The books known as "apocryphal" to Protestants are defined by Catholics as "Deuterocanonical" (a second canon). They come from the Septuagint, a Greek translation (with these additional books) of the Hebrew Tanakh. Later, around the 4th century, the Old Testament was translated by St. Jerome into Latin as part of the Vulgate. Besides the Catholic Church, the Constantinople-based Eastern Orthodox Church also received Deuterocanonical books as canonical.
Catholic Church considers the Deuterocanonicals on the same level as other books in the OT and NT canon. It is not a separate list, as expressed in the Catechism of the Catholic Church (CCC) article 120. The Deuterocanonicals are also "infallible", as expressed in CCC article 107; they are without error.
This topic has been debated from the beginning, even by St. Jerome himself as he made the Vulgate. He considered some of the books and texts not found in Hebrew to be apocryphal, as expressed in his prologue to the book of Kings, Esdras, Solomon, Jeremias and Judith. But later, throughout the Middle Ages, the Vulgate was accepted as the official translation by the Church (Western Catholic and Eastern Orthodox). After Luther's Germanic Bible in 1534, this issue became one of the points of difference between the "Old Churches" (Western Catholic and Eastern Orthodox) and "Protestant and Reformed Churches" (Luther and Calvin).