This sacrament is called Confirmation, because the faith given in Baptism is now confirmed and made strong, completing the graces received at Baptism. This strength aids in the spiritual duty to fight the war between good and evil, light and darkness — the war between the human race and all the powers of hell.
Confirmation means accepting responsibility for your faith and desetiny. The focus is on the Holy Spirit, who confirmed the apostles on Pentecost (Acts 2:1-4) and gave them courage to practice their faith. Catholics believe that the same Holy Spirit confirms Catholics during the Sacrament of Confirmation and gives them the same gifts and fruits.
Normally only the bishop confirms the Catholics in his diocese. However, priests can be delegated to confirm adult converts from other religions when they're brought into full communion with the Roman Catholic Church at the Easter Vigil and they've attended the Rite of Christian Initiation of Adults (RCIA) program in the parish. Non-Catholics who are interested in the Catholic faith and converting to Catholicism attend RCIA classes.