Simply Confirmation is what Baptism in the Spirit is to some denominations. They say it this way because they don’t believe they receive the Holy Spirit in water Baptism. Confirmation is a “strengthening” or the pouring out of the Spirit. Confirmation is seen in Acts 8:14-17 and 2 Cor 1:21.
Baptism in the Holy Spirit is something spoken of in the Charismatic movement, when you open yourself up to be docile to the Holy Spirit (and that’s I’ll say since there’s currently a moratorium on the Charismatic movement).
DISCLAIMER: Catholic Answers has turned over the archive to Catholic-Questions.org and no longer owns, manages, or moderates the forums. For additional apologetics resources please visit www.catholic.com.