CCC 833
Profession of Faith›SECTION TWO I. THE CREEDS›CHAPTER THREE I BELIEVE IN THE HOLY SPIRIT›Paragraph 3. THE CHURCH IS ONE, HOLY, CATHOLIC, AND APOSTOLIC
The phrase "particular church," which is the diocese (or eparchy), refers to a community of the Christian faithful in communion of faith and sacraments with their bishop ordained in apostolic succession. These particular Churches "are constituted after the model of the universal Church; it is in these and formed out of them that the one and unique Catholic Church exists."