According to the United States Conference of Catholic Bishops, a permanent deacon "is an ordained minister of the Catholic Church. There are three groups, or 'orders,' of ordained ministers in the Church: bishops, presbyters and deacons. Deacons are ordained as a sacramental sign to the Church and to the world of Christ, who came 'to serve and not to be served.'" In the United States, they typically have full-time jobs in addition to their ministry. Married men can be ordained as permanent deacons.
Deacons are formed according to the norms of the National Directory for the Formation, Ministry, and Life of Permanent Deacons in the United States (US Bishops, Second Edition, 2021), the Basic Norms for the Formation of Permanent Deacons, and the Directory for the Ministry and Life of Permanent Deacons (Congregation for Catholic Education and Congregation for the Clergy, 1998). Additionally, formation is ordered around four dimensions of formation -- human, intellectual, spiritual, and pastoral -- in the context of the ongoing discernment of the vocation to diaconal ministry and the call to Holy Orders.
The context for this discernment and formation is the deacon’s three-fold ministry as Servant of the Word, Servant of the Eucharistic Mystery, and Servant of the Charity of Christ.