Answer: Orthodox Christianity falls under the authority of various Patriarchates throughout the world. The oldest ones still active are in Istambul (aka Constantinople), Alexandria, Antioch and Jerusalem. The Russian patriarchate was added in about the 11th Century CE. Contrary to many people's opinion, the celebration of the liturgy IS different than the Roman Catholic and the differences are actually greater than simply "The Orthodox Church does not recognize the Pope as their leader"

The website in my sources can give you a LOT of information for your homework assignment.

There was a time when the Anglican (Church of England), Eastern Churches (Russian and Greek), and the Roman Catholic Church were roughly the same church. Both considered themselves as Orthodox and Catholic. In fact, even now each consider themselves as Catholic and Orthodox meaning each follows the orthodox views of practicing Christianity.

These "Orthodox" Churches follow sacraments and other similar rituals that were practiced years before Martin Luther founded the protestant movement. These "Non-Protestant" Churches have roughly the same rituals and practices.

The difference, however, is that each church (as a community) is headed by a different person. For the Anglican Church, the official head of the church is the Queen of England. For Eastern Orthodox, I don't really know. For the Roman Catholic Church, the pope is the head of the church.

So to put it short, Orthodox churches follow the same rituals as the Roman Catholic Church. The difference between them is that the Eastern Churches do not follow or are not headed by the Pope of the Roman Catholic Church.

Orthodox churches fall under the authority of the Patriarch in Russia. Roman Catholic churches fall under the authority of the Pope in Rome.

Other than that, there are minor differences like which Saints they honor on which day and the Orthodox churches tend to emphasize the Holy Spirit's role a bit more. They are essentially united in belief.