A parish is the lowest ecclesiastical subdivision in the administrative structure of the Orthodox Christian Church. While it is the smallest unit with regards to church administration it does not constitute a part of the Church, but the whole of the Church as whose universality or catholicity is confirmed by the real presence of Christ in the Divine Liturgy. Parishes are grouped into larger administrative bodies, varying in name per jurisdiction, such as deaneries which are subdivisions of dioceses or eparchies. Each parish is served by a parish priest, who may be assisted by other junior priests or by retired priests who are attached to the parish.
The word "parish" is also used in reference to the community (assembly) of people who attend a particular church that is served by a parish priest who has been entrusted with the position by the diocesan bishop.
During the early centuries of the Church the entire body of Christians in a city was under a bishop, much as the parish under a parish priest has been in later times. As Christianity spread into the country side from the fourth century on, the Christians in the major villages were organized into separate communities to which the bishop of the nearest city would assign a priest as their leader. These communities, served by a priest, came to be called parishes.
The word "parish" has its origins both in Scriptural use and from territorial references used in the Roman Empire. The word "parish" itself is derived from the Anglo-French parosse (about 1075), later as paroche (about 1292), then in Old French paroisse, and from Latin paroechia meaning a "diocese." In Greek, παρоικία (paroikia) meaning "district" or "diocese," which is derived from the Greek παρά (beside), οίκος (house). The Greek term παρоικία, "district" or "diocese," originally meant "sojourn in a foreign land" (in the Septuagint) or "community of sojourners," with reference to the Jewish people in a foreign land, later with reference to earthly life as a temporary abode (1st century A.D.), and also in the New Testament: 1 Peter 1:17, 2:11); whence the term was applied to the "Christian community" as a whole (3rd century), then to the "diocese" (3rd century), and ultimately "parish" (4th century).
The English language word "parish" is derived from the alternate Latin spelling parochia (which came from the Greek: πάροχος = "riding in the same chariot as," "beside the chariot of"), a local official in the Roman provinces who furnished public officials with food and other supplies when they passed through the local area.