In the Roman Curia of the Catholic Church, a congregation is a type of department of the Curia. They are second-highest-ranking departments, ranking below the two Secretariats, and above the pontifical councils, pontifical commissions, tribunals and offices.

The Holy See, also called the See of Rome, Petrine See or Apostolic See, is the jurisdiction of the pope in his role as the Bishop of Rome. It includes the apostolic episcopal see of the Diocese of Rome, which has ecclesiastical jurisdiction over the worldwide Catholic Church and sovereignty over the city-state known as the Vatican City. As the supreme body of government of the Catholic Church, the Holy See enjoys the status of a sovereign juridical entity under international law.