There are estimated to be over one billion Roman Catholics in the world. The majority of these are lay Catholics, also known as the laity, which includes all Roman Catholics, except those who are part of the clergy. The Catholic Church is overseen by the Pope, two hundred cardinals and just over 31,000 bishops. The Pope, cardinals, and bishops are known collectively as the Catholic Hierarchy and are responsible for the supervision, management, and pastoral care of all members the Catholic Church, including clergy, religious, and the laity.