What is a plenary indulgence?

Pope Francis said he will grant a plenary indulgence to the faithful who watch or listen to his extraordinary blessing “urbi et orbi” (to the city and the world) at 6 p.m. Rome time March 27. An indulgence is not a quick ticket to heaven, as St. John Paul II once said; rather, it is an aid for the real conversion that leads to eternal happiness.