Phrases concerning actions occurring within or outside an episcopal see are indicative of the geographical significance of the term, making it synonymous with diocese.
The word see is derived from Latin sedes, which in its original or proper sense denotes the seat or chair that, in the case of a bishop, is the earliest symbol of the bishop's authority. This symbolic chair is also known as the bishop's cathedra, and is placed in the diocese principal church, which for that reason is called the bishop's cathedral, from Latin ecclesia cathedralis, meaning the church of the cathedra. The word throne is also used, especially in the Eastern Orthodox Church, both for the seat and for the area of ecclesiastical jurisdiction.
Within Roman Catholicism, each diocese is considered to be a see unto itself with a certain allegiance to the See of Rome. The idea of a see as a sovereign entity is somewhat complicated due to the existence of the 23 Particular Churches of the Roman Catholic Church. The Western Church and its Eastern Catholic counterparts all reserve some level of autonomy, yet each also is subdivided into smaller sees (dioceses and archdioceses). The episcopal see of the Pope, the Bishop of Rome, is known as "the Holy See" or "the Apostolic See", claiming Papal supremacy.
The Eastern Orthodox Church views all bishops as sacramentally equal, and in principle holding equal authority, each over his own see. Certain bishops may be granted additional administrative duties over wider regions (as in the idea of the Pentarchy), but these powers are limited and never extend over the entire Church. Thus, the Eastern Orthodox oppose the idea of papal supremacy or any similar supremacy by any one bishop.