Holy See (OSV Encyc. 1997)
The Church is universal (which is what "Catholic" literally means); the message entrusted to her is for all mankind. The fact that the Church is often called the Roman Catholic Church does not indicate a limitation of its universality, but is rather a condition of it. A universal mission needs a reference point and a source of guidance to ensure, along with its fidelity to the will of Christ, the genuineness of its work of evangelization in all countries and continents. That reference point lies in Rome.
Each bishop has his "see" or area of jurisdiction. The "Holy See" is the See of Peter and his successors as Bishop of Rome, who by divine right have immediate and direct jurisdiction over the universal Church and over each diocese (which are also known as "particular churches").
The Pope has the care of all the local churches, not only to ensure that the means of salvation entrusted to his Church by Christ (doctrine and sacraments) are preserved everywhere (allowing for legitimate local variations or inculturations), but also to provide for administrative details that serve the good of Christ's faithful: the creation of dioceses according to demographic needs, the appointments of new bishops, etc. The Holy See is also a final court of appeal (above all through its Tribunals, the Apostolic Signatura and the Roman Rota) to which any member of the faithful anywhere can turn, who feels that his or her rights have not been respected by lower courts (Diocesan or Regional Appeal Courts).
The terms "Holy See" and "the Vatican" are often used as equivalent. The Vatican City State also exists as a state in its own right and has membership in the main international organisms designed to promote human welfare. This enables the Holy See to intervene internationally with the force of its moral authority, in the defense of the dignity of the person and genuine human progress and rights.
The "Dicasteries" or Departments of the "Roman Curia", which helps the Holy Father in his work of governing the Church, include the Secretariat of State, the Congregation for the Doctrine of the Faith, the Congregations of Bishops, of the Clergy, of Divine Worship, the Pontifical Councils for the Laity, for the Family, etc.