The Roman Catholic Church and the Eastern Greek Orthodox Church have some similarities and some differences between them.
The biggest and basic similarity is that they are both Christian churches, obey the Christian rules and their holy book is the bible.
The differences are:
- The Catholic Church has a Pope, while the Orthodox has Patriarch;
- The Catholic priests are not allowed to marry, while the Orthodox have to be married in order to become priests officially;
- The Catholic Church have traditionally had lot of power over the secular leaders, while the Orthodox Church was mostly controlled by the secular leaders;
- The Catholic Church sticks to the Gregorian calendar for the religious celebrations, while the Orthodox mostly sticks to the Julian calendar for the religious celebrations;
- The Catholic followers tend to go to church every Sunday, while the followers of the Orthodoxy rarely tend to go to the churches;