Can we call all Orthodox Churches and Protestant Churches a Catholic Denomination?
You can call the Orthodox Churches Catholic, in that Catholic means UNIVERSAL. There are Orthodox Churches all over the world. In fact,in the creed, they state that they believe “In one Holy, Catholic, and Apostolic Church” (Apostolic in this case means being handed down from the Apostles). There may be Protestant Churches that are “catholic” in that sense, such as those that are in the Anglican Communion.