The large majority of priests worldwide are diocesan priests. These men are ordained to work in a particular diocese or archdiocese. At the time of their ordination as deacons (usually about a year before their ordination as priests) they promise respect and obedience to the diocesan bishop and his successors. They also promise to live in chastity, and according to the status of clergy (which includes a comparatively simple life). Diocesan priests do not make vows, technically speaking, and do not promise poverty. Therefore, they may own their own property, such as cars, and handle their own financial affairs.
At deaconate ordination, the bishop accepts the promises of the deacon and priest, and thereby incardinates them into the diocese. This gives the transitional deacon and diocesan priest certain rights - such as the right to be supported by the diocesan church - and imposes on them the obligation to work for the diocesan church under the leadership of the bishop. This is a life-long commitment of mutual responsibility, although there are procedures in place by which a diocesan priest may choose to seek a transfer to a different diocese. Because most of the work of a diocese is done in parishes, a diocesan priest usually works in a parish. Some diocesan priests work in Catholic schools, as hospital chaplains, in administrative offices of the diocese, or in other places. Sometimes diocesan priests are called secular priests, because their main work is pastoral, i.e. to assist people who work in the contemporary world (Latin saeculum=world, the times).
Some priests are members of religious orders or institutes. A religious order or institute is an association established by the Church to promote a particular style of life or expression of spirituality, or to perform a specific type of work. Most religious communities of men work in more than one diocese, and many work worldwide. Each religious community has its own constitutions, and its members live according to a rule of life. All members of a religious community make vows or promises of poverty, chastity, and obedience. Some religious communities of men work in parishes, others do not. Religious priests work as hospital chaplains, retreat givers, teachers, itinerant preachers, parish priests, missionaries and in many other fields. Each community has its own charism, or gift of the Spirit. Priests who are members of a community bring that charism to their work.
The diocesan bishop supervises religious order priests when they are engaged in active ministry in his diocese, and no community can work in a diocese without his permission. The religious community's superior supervises the internal workings of the community. If a religious community serves the needs of a particular parish, it does so based on an agreement with the diocesan bishop.