A cardinal is a senior member of the clergy of the Catholic Church. As titular members of the clergy of the Diocese of Rome, they serve as advisors to the pope, who is the bishop of Rome and the visible head of the worldwide Catholic Church. Cardinals are chosen and formally created by the pope, and typically hold the title for life. Collectively, they constitute the College of Cardinals. The most solemn responsibility of the cardinals is to elect a new pope in a conclave, almost always from among themselves, with a few historical exceptions, when the Holy See is vacant.
During the period between a pope's death or resignation and the election of his successor, the day-to-day governance of the Holy See is in the hands of the College of Cardinals. The right to participate in a conclave is limited to cardinals who have not reached the age of 80 years by the day the vacancy occurs. With the pope, cardinals collectively participate in papal consistories, in which matters of importance to the Church are considered and new cardinals may be created. Cardinals of working age are also often appointed to roles overseeing dicasteries (departments) of the Roman Curia, the central administration of the Catholic Church.
