There are about 13 recognized books in what is known as the Apocrypha. During the years of growth the Greek culture enjoyed in Palestine, many books were written by the Jews.
These books were never considered as Scriptures by Christ or the Apostles. The early church saw lessons that were profitable in some of these books. However, there is such a mixed character about these books, they have always been treated with care by the church.
The great Bible teacher Harry Ironside explains the difference.
"But all of these were written ere the voice of prophecy was suspended; all the books now in our Bibles, and none other, were in the Bible loved, quoted and honored by the apostles, and endorsed as divinely-given by the Lord Jesus. He expressly refers to "Daniel the prophet," and "the sign of the prophet Jonah," in language that admits of no doubt as to the high plane on which He placed their writings. But in the Maccabean age and later there were other books of instructive character, making no claim of inspiration, which the Jews have always valued, and which the early Christians sometimes read in their meetings for the sake of the lessons they contained, though with no thought of putting them on a level with the Hebrew Scriptures or the Greek New Testament."
Taken from "Lessons of these 400 Silent Years" by Discover the Book Ministries (used by permission).