It is the Sacrament of ordination to Priesthood which includes three degrees: Episcopate, Presbyterate and Diaconate.
“As successors of the Apostles and members of the [episcopal] college, the bishops share in the apostolic responsibility and mission of the whole Church under the authority of the Pope, successor of St. Peter.”
Priests are united with the bishops in sacerdotal dignity… They are co-workers of the bishop from they receive the charge of parish community or some other ecclesial office.
Deacons are ordained ministers for service in the Church. “(…) they do not receive the ministerial priesthood, but ordination confers on them important functions in the ministry of the word, divine worship, pastoral governance and the service of charity…”
“The sacrament of Holy Orders is conferred by laying on of hands followed by a solemn prayer of consecration asking God to grant the ordinand the graces of the Holy Spirit required for the ministry. Ordination imprints an indelible sacramental character.