Could you explain the differences between a diocese an eparchy and exarchate?
Essentially the terms refer to the same thing but in different branches of the Church reflecting Christian traditions in various parts of the world. In the Catholic Church there are two primary liturgical groupings a Latin Church which has its roots in the western half of the Roman Empire and an Eastern Church which has its roots in the eastern half of the Roman Empire. While the Eastern branch was often called Greek or Oriental or Byzantine the reality is it was normal for those churches to use the traditions and language of the area and thus are more often referred to by their geographical, ethnic or linguistic roots. An Eastern eparchy or exarchate is the equivalent of a Latin diocese, an Eastern archeparchy the equivalent of a Latin archdiocese.
In my parishes we had members of various Eastern Churches. Because of the smaller number of their churches in the US, and the distance they would have to travel to attend those churches, many attend the Latin Rite churches.
In the same pattern as the Latin Church, the Eastern Catholic Churches have their own system of “dioceses”. Autonomous from Latin dioceses, these eparchies and exarchates overlap each other and the same geographical areas as the Latin dioceses as they serve the Eastern Catholic population of the U.S.
Countenance of God 