The Catechism in Questions & Answers

491. What is the relationship between Holy Baptism with water and Holy Sealing?

Holy Baptism with water and Holy Sealing are two distinct sacraments, however they are closely linked to one another: by receiving both sacraments, the individual is reborn out of water and the Holy Spirit. In the process, Holy Baptism with water precedes Holy Sealing.

Rebirth out of water and the Spirit: see Question 528. et seq.