Cardinals are chosen by the Holy Father to serve as his principal assistants and advisers in the central administration of church affairs. Collectively, they form the College of Cardinals. Provisions regarding their selection, rank, roles, and prerogatives are detailed in Canons 349 to 359 of the Code of Canon Law.

Cardinals under the age of 80 elect the Pope when the Holy See becomes vacant; and are major administrators of church affairs, serving in one or more departments of the Roman Curia. Cardinals in charge of agencies of the Roman Curia and Vatican City are asked to submit their resignation from office to the Pope on reaching the age of 75. A cardinal's title, while symbolic of high honor, does not signify any extension of the powers of holy orders.