Catechism of the Catholic Church §1024 — excerpt
This perfect life with the Most Holy Trinity - this communion of life and love with the Trinity, with the Virgin Mary, the angels and all the blessed - is called "heaven."
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.