Through the sacrament of holy orders, an ordination to priesthood is performed by the bishop. But this requires the consent of the whole people of God, so at a point in the service, the congregation acclaim the ordination by shouting Axios! (He is worthy!)
Orthodox priests consist of both married clergymen and celibate clergymen. In the Orthodox Church a married man may be ordained to the priesthood. His marriage, however, must be the first for both him and his wife. He may not remarry and continue in his ministry even if his wife should die.
If a single, or unmarried, or celibate, man is ordained, he must remain celibate to retain his service. A celibate priest is not necessarily the same as that of clergymen who are monastics, as celibacy does not automatically entail monasticism, though Orthodox monasticism does denote a call to celibacy. A priest-monk is called a hieromonk.