The Catholic Church
The word "Catholic" is a Greek word meaning "throughout whole", that is "Cath" meaning "through" and "holi" meaning "whole". It means fullness of belief and gives a comprehensive view of reality.
The Catholic Church is really a "communion of communions", comprising many different particular churches called dioceses. Each diocese has a number of cells called parishes.
Worldwide the Catholic Church numbers about 1.3 billion members, about 18% of the world's population.
The Pope is the head of the church, considered the Vicar of Christ on earth. The Bishops around the world, who are Vicars of Christ in their own dioceses, work in communion with the Pope in a collegial way. The papal or Petrine ministry is to keep the churches in Catholic communion with one another. You will find almost every ethnic group represented in the universal Catholic Church on all seven continents today.