Vocation to the ordained ministry is another way of saying vocation to the clerical state.
Those in the clerical state are those men who are called to serve the Church as Deacons, Priests, or Bishops.
Clerics are not better than the laity (those who are not ordained) but are called to serve them in a particular way.
They dedicate their lives to the service of the People of God in the Church.
By ordination, or the Sacrament of Holy Orders, they are configured to Christ for the service of the Church.
Prayer for vocations to the Ordained Ministry:
"Almighty God, look mercifully upon thy Church, and incline the hearts of many of her sons to offer themselves for the work of the Sacred Ministry, so that by their labour thy light may shine in the darkness of the world, and the coming of thy Kingdom may be hastened by the perfecting of thine elect; through Jesus Christ our Lord, who liveth and reigneth with thee, in the unity of the Holy Ghost, one God, world without end. Amen."