Catechism of the Catholic Church §2626 — excerpt
Blessing expresses the basic movement of Christian prayer: it is an encounter between God and man. In blessing, God's gift and man's acceptance of it are united in dialogue with each other.
This translation is under copyright, so only the cited words are quoted here. Follow the link for the full text. Translation: English translation of the Catechism of the Catholic Church, 2nd ed. (Libreria Editrice Vaticana), as posted at vatican.va.