Catechism of the Catholic Church §1498 — excerpt
Through indulgences the faithful can obtain the remission of temporal punishment resulting from sin for themselves and also for the souls in Purgatory.
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.