"Holy Orders is the sacrament through which the mission entrusted by Christ to his apostles continues to be exercised in the Church until the end of time: thus it is the sacrament of apostolic ministry. It includes three degrees: episcopate, presbyterate, and diaconate." ~Catechism of the Catholic Church - 1536
A Definition of the Three Degrees of the Sacrament of Holy Orders
Bishops (episcopate) are those who have care of multiple congregations and have the task of appointing, ordaining, and disciplining priests and deacons. They are often called 'evangelists' in the New Testament. Examples of first century bishops include Timothy and Titus (1 Tim. 5:19-22, 2 Tim. 4:5, Titus 1:5).
Priests (presbyterate) are also known as "presbyters" or "elders." In fact, the English term "priest" is simply a contraction of the Greek word "presbuteros." They have the responsibility of teaching, governing, and performing the sacraments in a given congregation (1 Tim. 5:17, Jas. 5:14-15).
Deacons (diaconate) are the assistants of the bishops and have the task of teaching and administering certain church functions, such as the distribution of food (Acts 6:1-6).
Are you interested in pursuing this sacrament? Begin your discernment process by perusing the Archdiocesan Vocation Website.