Diocesan bishops

A diocesan bishop, within various religious denominations, is a bishop (or archbishop) in pastoral charge of a(n arch)diocese (his (arch)bishopric), as opposed to a titular bishop or archbishop, whose see is only nominal, not pastoral.

In relation to other bishops, a diocesan bishop may be a suffragan, a metropolitan (if he is an archbishop) or a primate, and may also hold various positions such as cardinal or patriarch.

Titular (arch)bishops, on the other hand, may be assistant bishops, coadjutor bishops, auxiliary bishops, nuncios or similar papal diplomats, officials of the Roman Curia, etc., and likewise may also hold other positions such as cardinal.

A "diocesan bishop" — in the Catholic Church — is entrusted with the pastoral care of a local Church (diocese), over which he holds ordinary jurisdiction. He is responsible for teaching, governing, and sanctifying the faithful of his diocese, sharing these duties with the priests and deacons who serve under him.

The Holy See can appoint a coadjutor bishop for a diocese. He has special faculties and the right of succession.

The diocesan bishop may request that the Holy See appoint one or more auxiliary bishops, to assist him in his duties.

...
Wikipedia