"While they were worshiping the Lord and fasting, the Holy Spirit said, “Set apart for me Barnabas and Saul for the work to which I have called them.” Acts 13:2
The are three orders (or types) of ordained ministry: deacons, priests, and bishops. The process of entry into these orders is called ordination. All ordained people begin their lives as deacons, some become priests, and a small few bishops. Although each order has different responsibilities they are cumulative. That means that a priest is also a deacon, and that a bishop is both a deacon and a priest.