What is the Biblical Canon?

What is the canon of the Bible? Why does it matter? What is the differences between Protestant and Catholic Bibles? Did the Catholic Church add books? Or did the Reformers remove books? What are these so-called deuteron-canonical or apocryphal books? And what are the so-called “lost books of the Bible”? #biblicalcanon, #apocrypha, #biblestudy, #bible