The answer is that it's complicated. Let me start from the beginning. The Jewish canon (Tanakh) has 39 books — or 24 depending on how it is counted, since some Jews consider all the minor prophets to be one book. The Early Christian communities had a considerably larger canon than we have today. So, for example, St. Irenaeus considered the
Shepard of Hermas to be a sacred text. The Roman Catholic deuterocanonical books/apocrypha are books that were widely read by the Early Christians but that were not considered to be a part of the Jewish canon. In other words, books like Tobit and Sirach were popular amongst Christian communities but not amongst the Rabbinical Jewish communities. Roman Catholics include these books within our Sacred Scripture because they were revered by the early Church. Protestants make the argument that since the deuterocanonical books were not accepted by the Jews, they should not be accepted by Christians. Protestants usually view the deuterocanonical books as an infection of tradition upon
sola scriptura. Therefore, it is not so easy to say whether the Roman Church added these or whether the Protestants removed them. Perhaps we can say that the Early Christians added the deuterocanonical books to the Jewish canon and then the Protestants removed from the Christian canon. It is crucial to keep in mind that until the 4th century there was no official biblical canon for Christians. Manuscripts were scarce so a given Church might only possess a singular gospel book.
The Roman interpretation of the Ten Commandments does differ from the Protestant interpretation, and both differ from the Jewish interpretation. What we have to keep in mind that the ten commandments are never numbered. If the number ten were not mentioned, there could be as many as fourteen separate commandments contained in the passage in
Exodus 20. The main difference between the Protestant and Catholic readings is that Roman theology reads" "You shall have no other gods before me.You shall not make for yourself a carved image, or any likeness of anything that is in heaven above, or that is in the earth beneath, or that is in the water under the earth," as the first commandment. Protestants object and say that this is a ploy by the Roman Church to justify their saint statues and prayers to saints. Protestants interpret these as two commandments with the second being about statues. In other words, Catholics read these passages as condemning making false idols, not all religious imagery and Protestants (by reading the passages separately) read it as a condemnation of all religious statues. Roman Catholics point to passages in the Old Testament where the Jewish people were instructed to build religious statues to defend their reading of the ten commandments: "And you shall make two cherubim of gold; of hammered work shall you make them, on the two ends of the mercy seat" (
Exodus 25:18). I am not entirely sure how Protestants justify their position. I am not nearly as learned in Protestantism as I am in Roman Catholcism.