The answer is -as Catholics themselves are generally unaware- that they have millions of co-religionists who are not themselves part of the Roman Catholic Church. So who are these "other" Catholics? They have their own hierarchies and liturgies, as well as their own distinct apostolic lineages, but they recognize the pope of
“These individual Churches, whether of the East or the West, although they differ somewhat among themselves in rite (to use the current phrase), that is, in liturgy, ecclesiastical discipline, and spiritual heritage, are, nevertheless, each as much as the others, entrusted to the pastoral government of the Roman Pontiff, the divinely appointed successor of St. Peter in primacy over the universal Church,” the Decree on The Catholic Churches of the Eastern Rite (Orientalium Ecclesiarum) declared. Similar documents explain this “unity in diversity” as put together in the Magisterium section.
Several articles in the Features section explain who they are and what caused the division. This is indeed one of the most tragic divisions within Christianity.
So we may appreciate “the whole picture”, the Roman Catholic Church comprises 22 individual or sui juris Churches, all in full communion with the Church of Rome, forming the One, Holy, Catholic, and Apostolic Church. There is the Latin Church, and 21
John Paul II had spoken of “making the