The article itself answers that question:
Note: Members of the Eastern Orthodox Church do not usually refer to themselves as “Eastern” Orthodox but rather with a prefix denoting their nation of origin. Thus, within this article, the terms “Greek”, “Russian”, or any other “National” Orthodox; as well as
The Church, The Orthodox Church, The Byzantine Church, etc., all refer to a single unified entity, what is today commonly called the Eastern Orthodox Church.
Several other ancient churches in Eastern Europe, Western Asia, and North Africa also use the term “Orthodox”, but are distinct from the “Eastern Orthodox Church” as described in this article. See
Oriental Orthodoxy.
Historically, the Orthodox Churches have been the Greek-literate churches associated with Alexandria,
Constantinople (
Istanbul), and other Hellenized cities, while the Roman church was associated with Latin Rome and the West. This distinction grew with the division of the Roman Empire into East and West.
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