Catechism of the Catholic Church §1188 — excerpt
In a liturgical celebration, the whole assembly is leitourgos, each member according to his own function. the baptismal priesthood is that of the whole Body of Christ.
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.