Catechism of the Catholic Church §779 — excerpt
The Church is both visible and spiritual, a hierarchical society and the Mystical Body of Christ. She is one, yet formed of two components, human and divine.
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.