Simplify the following text for a Grade 10 native English-speaking person.
Original: The Eastern Orthodox Church has thought of itself in the same way , but in the late 20th century there has been much more discussion between the Orthodox Church and Roman Catholic , Lutheran and Anglican Churches .
Simplified: In the same manner , the Roman Catholic Church describes itself as orthodox , meaning having possession of the whole faith . Other Christian denominations , who do not accept the claims of this Church to be the sole orthodox Church refer to her as the Eastern Orthodox Church .