A diocesan bishop, within various Christian traditions, is a bishop or archbishop in pastoral charge of a diocese or archdiocese. In relation to other bishops, a diocesan bishop may be a suffragan, a metropolitan (if an archbishop) or a primate. They may also hold various other positions such as being a cardinal or patriarch.
Titular bishops in the Roman Catholic Church may be assistant bishops with special faculties, coadjutor bishops (these bishops are now named as coadjutors of the dioceses they will lead, and not as titular bishops), auxiliary bishops, nuncios or similar papal diplomats (usually archbishops), officials of the Roman Curia (usually for bishops as heads or deputies of departments who are not previous ordinaries), etc. They may also hold other positions such as cardinal. The see of titular bishop is only nominal, not pastoral- meaning he does not exercise final authority as the head bishop (the ordinary), or have the right to automatically succeed the aforementioned individual (the coadjutor), over an existing diocese or archdiocese or their Eastern rite equivalents, (arch-)eparchies. Titular bishops may be active or retired. Occasionally, as a priest, they may have been given a titular bishopric or archbishopric as an honor by the Pope, similar to when he names some cardinals.[1]