The Cardinals constitute a special college, and they assist the Roman Pontiff collegially when they are called together to deal with questions of major importance; they do so individually when they assist the Pope especially in the daily care of the universal Church by means of the different offices which they perform (canons 349350). The Cardinals who are under eighty years of age elect his successor.
The College of Cardinals is divided into three ranks: Cardinal-Bishops, Cardinal-Priests, and Cardinal-Deacons. The College of Cardinals, when complete formerly consisted of 70 members; 6 Cardinal Bishops, 50 Cardinal Priests and 14 Cardinal Deacons, but the late Pontiffs, Pope John XXIII and Pope Paul VI enlarged the College of Cardinals. At the moment the maximum number of Cardinal electors (those under 80 years of age) must not exceed 120.
The Cardinal Bishops (except the Patriarch-Cardinals of the Oriental Rites), have as Titular Sees the Suburban Sees of Rome, which are: Porto Santa Rufina, Albano, Palestrina, Sabina, Frascati, Velletri, Segni. The Cardinal Dean has united to his See the See of Ostia. The Cardinal Priests take their title from the “Titular Churches” to which they are appointed: the Cardinal Deacons are appointed to other Churches called “Deaconries”. The first Cardinal Bishop is Dean; the first Cardinal Priest is First Priest; and the first Cardinal Deacon is First Deacon of the Sacred College.
The Dean has the right of ordaining the new Pope if he is not already a bishop; the First Deacon the right of proclaiming him and investing him with the sacred Pallium. On the death of the Pontiff, the Cardinal Camerlengo has the Administration of the affairs of the Holy See.
Sometimes the Roman Pontiff promotes a person to the dignity of Cardinal but does not make public his name and keeps it “in pectore”. Upon the publication of his name, this Cardinal enjoys his right of precedence from the day on which his name was reserved “in pectore” by the Pope (cfr. Can. 351 3).