Read about The Catholic Church
Catholicism is a broad term for the body of the Catholic faith, its theologies and doctrines, its liturgical, ethical, spiritual, and behavioral characteristics, as well as a religious people as a whole.
For many the term usually refers to Christians and churches, western and eastern, in full communion with the Holy See. For others it refers to churches with historical continuity from the first millennium.
In the sense of indicating historical continuity of faith and practice, the term "catholicism" is at times employed to mark a contrast to Protestantism, which tends to look solely to the Bible as interpreted on the principles of the 16th-century Protestant Reformation as its ultimate standard. It was thus used by the Oxford Movement.
Catholicism is distinguished from other forms of Christianity in its particular understanding and commitment to tradition, the sacraments, the mediation between God, communion, and the See of Rome.