The Catechism in Questions & Answers

476. What is the “content” in a sacrament?

The “content” is the effect that imparts salvation. In Holy Baptism with water, the “content” is the washing away of original sin and the fact that the baptised now enters into the proximity of God. In Holy Communion, it is partaking in the body and blood of Jesus. In Holy Sealing, the content is that the believer receives the gift of the Holy Spirit.