Cathedrals

The cathedral is the center of a diocese, in the same way that the Vatican is the center for the universal Church. The cathedral is the church in the diocese where the bishop's chair resides, which is the symbol of his authority as a successor to the apostles.

Ironically, St. Peter's Basilica in the Vatican, where the pope celebrates Mass, isn't the pope's cathedral church. That would be St. John Lateran, which served as the pope's residence until the move to the Vatican.

Bishops usually celebrate Mass in their cathedral. The diocese's cathedral is also the location for the Chrism Mass (also known as the Mass of the Oils), where men are ordained deacons, priests, and bishops. Cathedrals hold weekly and daily Mass in the same manner as other parishes, and can also host weddings, funerals, baptisms, and the like. However, the pride of the cathedral is its Chrism Mass.

Incidently, only the bishop can sit in his cathedra (chair). If another priest celebrates Mass at the cathedral, he must use a different seat.