WHAT IS HOLY ORDERS?
Holy Orders is a sacrament conferred on men and by which they carry on the apostolic tradition as ministers of the Gospel and the sacraments. The Church is made up of three orders: Episcopate (bishops), presbyterate (priests), and deaconate (deacons).

WHAT IS A VOCATION?
The term given to the call to each person from God; everyone has been called to holiness and eternal life, especially through Baptism. Each person can also be called more specifically to the priesthood (Holy Orders), to religious life, to married life (Holy Matrimony), or to single life, as well as to a particular profession or service.

This handout about Holy Orders from the United States Conference of Catholic Bishops provides more specifics.

The Office of Priestly Vocations of the Toledo Diocese helps young men better understand whether God is inviting them to serve the Church as an ordained priest.