Roman Catholicism refers to the theology and doctrine of the Christian church under the auspices of the Holy See, the papacy based in Rome. According to ecclesiastical scholars, Catholicism is distinguished from other branches of Christianity by its commitment to the church’s traditions, to the sacraments, and its priesthood as interpreters of the Bible.
The earliest known use of the term “Catholic Church” is by Ignatius of Antioch around 107 AD. The early church was organized based on the rule of three patriarchs, those of Rome, Alexandria and Antioch – to which were later added the patriarchs of Constantinople and Jerusalem. But too many patriarchs tend to muddy the holy waters.
Soon, the patriarch of Rome claimed special authority based on the connection between St. Peter and that city. For 1000 years, Roman Catholicism dominated Europe, until the Great Schism of 1054 AD that gave rise to Eastern Orthodoxy. Some 500 years later another major division in Christianity occurred with the Protestant Reformation, which saw many in Europe reject the teachings and practices of Catholicism in favor of more personal expressions of belief.
Presently, the Roman Catholic Church considers those not in communion with the Vatican to be “non-Catholics” but tolerates differing interpretations of the Bible. A bit of a shift from the days when it burned heretics and most everyone else who differed from the Catholic dogma.