The sacrament of Holy Orders is the activity by which a man commits his life to serve the Church. Holy orders is a three-fold sacrament in that it includes ordination to the diaconate, the priesthood and to the office of Bishop.
The deacon is ordained for service and can perform marriages, baptisms, assist at the altar during Mass and performs other rituals in the Church.
When a man is ordained to the priesthood he is given the responsibility and the power to offer Mass (the Eucharist), forgive sins, administer the other sacraments and care for the spiritual lives of the people he serves.
When a Bishop is ordained he accepts the responsibility to administer his diocese and has the personal jurisdiction as a successor of the apostles over the people in his diocese.
Whenever a young man feels called to the priesthood, or a young woman to consecrated religious life, it is appropriate for them to contact their pastor. His guidance will be extremely beneficial to them. Married adult men (age 35 or older) should likewise contact the pastor for information on becoming a deacon.