That the Holy Spirit Proceeds from Both the Father and the Son,
The state of Purgatory,
Original Sin.
the Eastern Orthodox Church and the Roman Catholic Church
The Eastern Orthodox Church split from the Roman Catholic Church in 1054, in an event known as the Great Schism.
No, the Pope is the head of the Roman Catholic church. The Ecumenical Patriarch is the head of the Eastern Orthodox Church.
the Eastern Orthodox Church
The Orthodox Churches and the Catholic Church were once united. The Orthodox Churches separated from the Catholic Church over political and doctrinal differences.
There are Eastern or Byzantine Rite Catholics but they are in full union with Rome as opposed to the Eastern Orthodox Churches which are not. There was a brief period in the 20th century, when a separate Orthodox Church broke away from the Eastern Orthodox Church in America and formed the America Orthodox Catholic Church. But it was yet another splinter of an already splintered Church. orthodox (small "O") means right belief, and thus is synonymous with Catholic. Now, there is also an Orthodox Catholic Church of America, also not in Communion with the Catholic Church. . You may read about the American Orthodox Catholic Church at the links below.
Roman Catholic AnswerThe Catholic Church is sometimes known as the Western Church to distinguish it from the Eastern Orthodox Church.
The catholic church is sometimes considered the collection of churches that developed out of the Great Schism (namely, the Roman Catholic Church and the Eastern Orthodox Church). Although I have never heard someone use the term "catholic orthodox church," I would consider it to be referring to the Eastern Orthodox Christian religion.
It was the Western Church that accepted the authority of the pope and celibacy. This led to the Great Schism in 1054, which resulted in the separation of the Roman Catholic Church in the West and the Eastern Orthodox Church in the East. The Eastern Orthodox Church did not recognize the authority of the pope and allowed married clergy.
Anyone other than Eastern Orthodox eg Oriental Orthodox, Catholic, Protestant
The Roman Catholic Church and the Eastern Orthodox Church split in 1054 due to disagreements over the authority of the Pope, theological differences, and cultural and political divisions.
It is when The Roman Catholic Church and The Eastern Orthodox Church had The Great Schism, in which The Roman Catholic Church broke off The Orthodox Church.