In the Catholic Church, a deacon is an ordained minister who holds the first level of the sacrament of Holy Orders—the other two being priest and bishop. The diaconate, the order of deacons, is considered a ministry of service and charity.
Deacons have a threefold role of service, defined in terms of service to the Word, to the Sacrament, and to Charity. They can proclaim the Gospel during Mass, preach homilies, lead prayers, and conduct funeral and burial services. They can also baptize, witness marriages, and distribute Communion.
There are two types of deacons in the Catholic Church: transitional and permanent.
Transitional deacons are seminarians, men in the process of becoming ordained priests. They are usually ordained to the diaconate after completing their third year at the theological seminary. After a period of service as a deacon, they are then ordained as priests.
Permanent deacons, on the other hand, can be married or single. Married men can be ordained as permanent deacons, and single men may be ordained with a commitment to celibacy. They usually have secular jobs while also serving in their parishes, and their responsibilities can include pastoral care, teaching, hospital or prison ministries, and other forms of social service.
In the Catholic Church, a deacon can perform some, but not all, of the sacraments:
However, deacons cannot celebrate Mass (i.e., consecrate the bread and wine into the Body and Blood of Christ), hear confessions, or anoint the sick—these sacraments are reserved for ordained priests. Additionally, the sacrament of Holy Orders can only be administered by a bishop.
The role of a deacon, overall, is to assist priests and bishops in their pastoral and administrative duties and to be a symbol of the call to service in the Catholic Church.