Catholic church and Eastern Church

Catholic church noun - Any of several churches claiming to have maintained historical continuity with the original Christian Church.

Eastern Church and Catholic church are semantically related. In some cases you can replace phrase "Eastern Church" with "Catholic church", this phrases are similar.

Eastern Church noun - Derived from the Byzantine Church and adhering to Byzantine rites.

Catholic church and Eastern Church are semantically related. You can use "Catholic church" instead a noun phrase "Eastern Church".