Secular—or better, diocesan—priests are priests who are ordained for a particular diocese and who serve ordinarily in parishes. This is their main work, although some are engaged in other ministries as well. At their ordination as deacons they incardinate (affiliate) with a particular diocese or archdiocese. At this time they make a promise to obey their bishop and, in the Western Church, to remain celibate.
Clergy who are engaged for the most part in pastoral work and who are not members of a religious institute. They are not bound by a vow of poverty or community life. But their celibacy, in the Latin Church, is under solemn oath and they promise obedience to a bishop as their immediate superior under the Pope.