A primate is the presiding bishop of an ecclesiastical jurisdiction or region. Usually, primate refers to the first hierarch of an autocephalous or autonomous Orthodox Church. Less often, it is used to refer to the ruling bishop of an archdiocese or diocese.
The primate is the first among equals of all his brother bishops of the jurisdiction or diocese of which he is first hierarch, and he is usually elected by the Holy Synod in which he will serve. All bishops are equal sacramentally, but the chief administrative tasks are done by the bishop of the most honored diocese.
The primate of an autocephalous church, supervises the internal and external welfare of that church and represents it in its relations with other Autocephalous Orthodox Churches, religious organizations, and secular authorities.
His name is mentioned during liturgical services by the other bishops of the autocephalous church. The primate mentions the names of the other heads of autocephalous Orthodox Churches at Devine services.
Liturgical duties varies from jurisdiction to jurisdiction, but normally this hierarch is responsible for such tasks as: the consecration and distribution the Holy Chrism; providing the diocesan bishops with the Holy Relics necessary for the consecration of church altars and Holy Antimins.
Administrational duties may include: the convening and presiding over the meetings of the Holy Synods and other councils; receives petitions for admission of clergy from other Orthodox Churches; initiates the action to fill vacancies in the office of diocesan bishops; issues pastoral letters addressed to the bishops, clergy, and laity of the Church.
He also: gives advice to his brother bishops, and in cases of necessity, submits their cases to the Holy Synod; has the honor of pastoral initiative and guidance, and when necessary the right of pastoral intervention, in all matters concerning the life of the Church within the structure of the holy canons.