A bishop in the Catholic Church is an ordained minister who holds the fullness of the sacrament of Holy Orders and is responsible for teaching doctrine, governing Catholics in his jurisdiction, sanctifying the world and representing the Church. Bishops are considered the successors of the apostles, and they form a body, known as the College of Bishops, with the Pope as their head.
In their diocese (a geographical area designated to a bishop), they are the principal teachers, sanctifiers, and pastors. They conduct religious services, administer the sacraments (especially Confirmation and Holy Orders), oversee the administration of the diocese, and implement church laws and regulations.
Bishops can also be appointed to special roles beyond that of the leadership of a diocese. These include cardinals (who are usually bishops), who have the additional responsibility of electing the Pope and serving as his principal advisors, and archbishops, who typically oversee larger or more important dioceses known as archdioceses.
A bishop plays a critical role in the governance, pastoral care, and spiritual leadership within the Catholic Church.