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. Depending on the understanding of the word "Catholic", it may refer to the Roman Catholic Church, namely the Christians living in communion with the Church of Rome. More broadly, it refers to many churches, including the Roman Catholic Church and others not in communion with it, that claim continuity with the Catholic Church before separation into Greek or Eastern and Latin or Western. Churches that make this claim of continuity include the Roman Catholic Church, the Eastern Orthodox Church, the Oriental Orthodox churches, the Assyrian Church of the East,the Old Catholic churches and the churches of the Anglican Communion. The claim of continuity may be based on Apostolic Succession, especially in conjunction with adherence to the Nicene Creed. Some interpret Catholicism as adherence to the traditional beliefs that Protestant Reformers were denied, as with 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, and communion. Catholicism can include a monastic life, religious orders, a religious appreciation of the arts, a communal understanding of sin and redemption, missionary activity, and, in the Roman Catholic Church, papacy.
The earliest recorded evidence of the use of the term "Catholic Church" is the Letter to the Smyrnaeans that Ignatius of Antioch wrote in about 107 to Christians in Smyrna.  Saint Ignatius used the term to designate the Christian Church possessing true traditions, excluding heretics, such as those who "confess not the Eucharist to be the flesh of our Saviour Jesus Christ, which suffered for our sins, and which the Father, of His goodness, raised up again." Exhorting Christians to remain closely united with their bishop, he wrote: "Wherever the bishop shall appear, there let the multitude [of the people] also be; even as, wherever Jesus Christ is, there is the Catholic Church."
Yet more explicit was the manner in which Cyril of Jerusalem (circa 315–386) used the term "Catholic Church" precisely to distinguish it from other groups that also claimed the title of "Church." Only slightly later, Saint Augustine of Hippo (354–430) wrote:
In the Catholic Church, there are many other things which most justly keep me in her bosom. The consent of peoples and nations keeps me in the Church; so does her authority, inaugurated by miracles, nourished by hope, enlarged by love, established by age. The succession of priests keeps me, beginning from the very seat of the Apostle Peter, to whom the Lord, after His resurrection, gave it in charge to feed His sheep (Jn 21:15–19), down to the present episcopate.
And so, lastly, does the very name of Catholic, which, not without reason, amid so many heresies, the Church has thus retained; so that, though all heretics wish to be called Catholics, yet when a stranger asks where the Catholic Church meets, no heretic will venture to point to his own chapel or house.
Such then in number and importance are the precious ties belonging to the Christian name which keep a believer in the Catholic Church, as it is right they should ... With you, where there is none of these things to attract or keep me... No one shall move me from the faith which binds my mind with ties so many and so strong to the Christian religion... For my part, I should not believe the gospel except as moved by the authority of the Catholic Church. —St. Augustine (354–430): Against the Epistle of Manichaeus called Fundamental, chapter 4: Proofs of the Catholic Faith.
On 27 February 380, by an edict issued in Thessalonica and published in Constantinople, Emperor Theodosius declared Catholic Christianity the official religion of the Roman Empire, and defined the term "Catholic" in Roman Imperial law as follows:
It is our desire that all the various nations which are subject to our clemency and moderation, should continue the profession of that religion which was delivered to the Romans by the divine Apostle Peter, as it has been preserved by faithful tradition and which is now professed by the Pontiff Damasus and by Peter, Bishop of Alexandria, a man of apostolic holiness. According to the apostolic teaching and the doctrine of the Gospel, let us believe in the one Deity of the Father, Son and Holy Spirit, in equal majesty and in a holy Trinity. We authorize the followers of this law to assume the title Catholic Christians; but as for the others, since in our judgment they are foolish madmen, we decree that they shall be branded with the ignominious name of heretics, and shall not presume to give their conventicles the name of churches. They will suffer in the first place the chastisement of divine condemnation and the second the punishment of our authority, in accordance with the will of heaven will decide to inflict. Theodosian Code XVI.i.2
A contemporary of Augustine, St. Vincent of Lerins, wrote in 434 under the pseudonym Peregrinus a work known as the Commonitoria ("Memoranda"). While insisting that, like the human body, Church doctrine develops while truly keeping its identity (sections 54–59, chapter XXIII), he stated: "[I]n the Catholic Church itself, all possible care must be taken, that we hold that faith which has been believed everywhere, always, by all. For that is truly and in the strictest sense 'Catholic,' which, as the name itself and the reason of the thing declare, comprehends all universally. This rule we shall observe if we follow universality, antiquity, consent. We shall follow universality if we confess that one faith to be true, which the whole Church throughout the world confesses; antiquity, if we in no wise depart from those interpretations which it is manifest were notoriously held by our holy ancestors and fathers; consent, in like manner, if in antiquity itself we adhere to the consentient definitions and determinations of all, or at the least of almost all priests and doctors" (section 6, end of chapter II).
For some confessions listed under category 2, the self-affirmation refers to the belief in the ultimate unity of the universal church under one God and one Saviour, rather than in one visibly unified institution (as with category 1, above). In this usage, "catholic" is sometimes written with a lower-case "c". The Western Apostles' Creed and the Nicene Creed, stating "I believe in ... one holy catholic ... church", are recited in worship services. Among some denominations in category 3, "Christian" is substituted for "catholic" in order to denote the doctrine that the Christian Church is, at least ideally, undivided.  
According to the theory of Pentarchy, the early Catholic Church came to be organised under the three patriarchs of Rome, Alexandria and Antioch, to which later were added the patriarchs of Constantinople and Jerusalem. The Bishop of Rome was at that time recognized as first among them, as is stated, for instance, in canon 3 of the First Council of Constantinople (381)—many interpret "first" as meaning here first among equals—and doctrinal or procedural disputes were often referred to Rome, as when, on appeal by St Athanasius against the decision of the Council of Tyre (335), Pope Julius I, who spoke of such appeals as customary, annulled the action of that council and restored Athanasius and Marcellus of Ancyra to their sees. The Bishop of Rome was also considered to have the right to convene ecumenical councils. When the Imperial capital moved to Constantinople, Rome's influence was sometimes challenged. Nonetheless, Rome claimed special authority because of its connection to Saint Peter.  and Saint Paul, who, all agreed, were martyred and buried in Rome, and because the Bishop of Rome saw himself as the successor of Saint Peter.
The 431 Council of Ephesus, the Third Ecumenical Council, was chiefly concerned with Nestorianism, which emphasised the distinction between the humanity and divinity of Jesus and taught that, in giving birth to Jesus Christ, the Virgin Mary could not be spoken of as giving birth to God. This Council rejected Nestorianism and affirmed that, as humanity and divinity are inseparable in the one person of Jesus Christ, his mother, the Virgin Mary, is thus Theotokos, God-bearer, Mother of God. The first great rupture in the Church followed this Council. Those who refused to accept the Council's ruling were largely Persian and are represented today by the Assyrian Church of the East and related Churches, which, however, do not now hold a "Nestorian" theology. They are often called Ancient Oriental Churches.
The next major break was after the Council of Chalcedon (451). This Council repudiated Eutychian Monophysitism which stated that the divine nature completely subsumed the human nature in Christ. This Council declared that Christ, though one person, exhibited two natures "without confusion, without change, without division, without separation" and thus is both fully God and fully human. The Alexandrian Church rejected the terms adopted by this Council, and the Christian Churches that follow the tradition of non-acceptance of the Council—they are not Monophysite in doctrine—are referred to as Pre-Chalcedonian or Oriental Orthodox Churches.
The next great rift within Christianity was in the 11th century. Longstanding doctrinal disputes, as well as conflicts between methods of Church government, and the evolution of separate rites and practices, precipitated a split in 1054 that divided the Church, this time between a "West" and an "East". England, France, the Holy Roman Empire, Poland, Bohemia, Slovakia, Scandinavia, the Baltic countries, and Western Europe in general were in the Western camp, and Greece, Romania, Russia and many other Slavic lands, Anatolia, and the Christians in Syria and Egypt who accepted the Council of Chalcedon made up the Eastern camp. This division is called the East-West Schism.
The fourth major division in the Church occurred in the 16th century with the Protestant Reformation, after which many parts of the Western Church either entirely rejected the teachings of the Roman Catholic Church and became known as "Reformed" or "Protestant", or else repudiated Roman papal authority and accepted decisions by the civil ruler in religious matters (e.g., in Anglicanism and parts of the Lutheran Church).
A much less extensive rupture occurred when, after the Roman Catholic Church's First Vatican Council, in which it officially proclaimed the dogma of papal infallibility, clusters of Catholics in the Netherlands and in German-speaking countries formed the Old-Catholic (Altkatholische) Church.
See main article: Roman Catholic Church.
The Roman Catholic Church is the world's largest single religious body and the largest Christian Church, comprising over half of all Christians and one-sixth of the world's population.  It comprises 23 "particular Churches," or Rites, all of which acknowledge a primacy of jurisdiction of the Bishop of Rome and are in full communion with the Holy See and each other. These particular Churches are the one Latin-Rite or Western Church (which uses a number of different liturgical rites, of which the Roman Rite is the best known) and 22 Eastern Catholic Churches. Of the latter particular Churches, 14 use the Byzantine liturgical rite.
See main article: Sui iuris.
See main article: Eastern Orthodox Church.
See main article: Oriental Orthodoxy.
See main article: Assyrian Church of the East.
The Eastern Orthodox and Oriental Orthodox Churches, as well as the Assyrian Church of the East, each consider themselves to be the universal and true Catholic Church. Each of these three regards the others — since the divisions at the Councils of Ephesus (431) and Chalcedonia (451) — as heretical or at least as schismatic and as having thus left the One, Holy, Catholic, and Apostolic Church.The patriarchs of the Eastern Orthodox and Oriental Orthodox Churches are autocephalous hierarchs, which roughly means that each is independent of the direct oversight of another bishop, although still subject, according to their distinct traditions, either to the synod of bishops of each one’s jurisdiction, or to a common decision of the patriarchs of their own communion. They are willing to concede a primacy of honor to the Roman See, but not of authority, nor do they accept its claim to universal and immediate jurisdiction. This is similar to the position taken by the Lutheran World Federation, the Anglican Communion, and the Old Catholic Church.
Within Western Christianity, the churches of the Anglican Communion, the Old Catholics, the Liberal Catholic Church, the Aglipayans (Philippine Independent Church), the Polish National Catholic Church of America, and many Independent Catholic Churches, which emerged directly or indirectly from and have beliefs and practices largely similar to Latin Rite Catholicism, regard themselves as "Catholic" without full communion with the Bishop of Rome, whose claimed status and authority they generally reject. The Chinese Patriotic Catholic Association, a division of the People's Republic of China's Religious Affairs Bureau exercising state supervision over mainland China's Catholics, holds a similar position.
See main article: Anglicanism. Introductory works on Anglicanism, such as The Study of Anglicanism, typically refer to the character of the Anglican tradition as "Catholic and Reformed", which is in keeping with the understanding of Anglicanism articulated in the Elizabethan Settlement and in the works of the earliest standard Anglican divines such as Richard Hooker and Lancelot Andrewes. Yet different strains in Anglicanism, dating back to the English Reformation, have emphasized either the Protestant, Catholic, or "Reformed Catholic" nature of the tradition.
Anglican theology and ecclesiology has thus come to be typically expressed in three distinct, yet sometimes overlapping manifestations: Anglo-Catholicism (or "high church"), "Evangelicalism" (or "low church"), and Latitudinarianism (or "broad church"), whose beliefs and practices fall somewhere between the two. Though all elements within the Anglican Communion recite the same creeds, Evangelical Anglicans regard the word catholic in the ideal sense given above. In contrast, Anglo-Catholics regard the communion as a component of the whole Catholic Church, in spiritual and historical union with the Roman Catholic, Old Catholic and several Eastern Churches. Broad Church Anglicans tend to maintain a mediating view, or consider the matter one of adiaphora.
The Catholic nature of the Anglican tradition is expressed doctrinally, ecumenically (chiefly through organisations such as the Anglican Roman Catholic International Commission), ecclesiologically (through its episcopal governance and maintenance of the historical episcopate), and in liturgy and piety. Anglicans (except neo-evangelicals) maintain belief in the Seven Sacraments, Anglo-Catholics practice Marian devotion, recite the rosary and the angelus, practice Eucharistic adoration, and seek the intercession of saints. In terms of liturgy, most Anglicans use candles on the altar, many churches use incense and sanctus bells in the Eucharist, which is often referred to by the Latin-derived word "Mass". In some churches the Eucharist is still celebrated facing the altar (often with a tabernacle) by a priest assisted by a deacon and subdeacon. Anglicans believe in the Real Presence of Christ in the Eucharist.
The growth of Anglo-Catholicism is strongly associated with the Oxford Movement of the nineteenth century. Two of its leading lights, John Henry Newman and Henry Edward Manning, both priests, ended up joining the Roman Catholic Church, becoming cardinals. Others, like John Keble, Edward Bouverie Pusey, and Charles Gore became influential figures in the Anglican Church. The current Archbishop of Canterbury, Rowan Williams, is a patron of the Anglican organisation, Affirming Catholicism, a liberal movement within catholic Anglicanism. Conservative catholic groups also exist within the tradition, such as Forward in Faith.
As in Orthodoxy, all thirty-eight provinces of the Anglican Communion are independent, each with its own primate and governing structure. These provinces may take the form of national churches (such as in Canada, Uganda, or Japan) or a collection of nations (such as the West Indies, Central Africa, or Southeast Asia). All are in union with the see of Canterbury.
The 38 provinces include:
In addition, there are six extra-provincial churches, five of which are under the metropolitical authority of the Archbishop of Canterbury.
There are Catholic groups among the Protestant churches. For example, The 20th century "High Church Lutheranism" movement developed an Evangelical Catholicity, combining justification by faith with Catholic doctrine on sacraments, in some cases also restoring lacking Apostolic Succession, especially in Germany.
In Reformed churches there is a Scoto-Catholic grouping within the Presbyterian Church of Scotland. Such groups point to their churches' continuing adherence to the 'Catholic' doctrine of the early Church Councils. The Articles Declaratory of the Constitution of the Church of Scotland of 1921 defines that church legally as 'part of the Holy Catholic or Universal Church'.
However, like in case of Anglican Church, the Roman Catholic Church does not accept that these other churches are Catholic, as it views communion with the Bishop of Rome as being an indispensable part of what it means to be Catholic; the maintenance of Apostolic Succession is necessary to be considered a Church.
Due to the divergent interpretations of the word "Catholicism," any listing of beliefs and practices that distinguish Catholicism from other forms of Christianity must be preceded by an indication of the sense employed. If Catholicism is understood as the Roman Catholic Church understands it, identification of beliefs is relatively easy, though preferred expressions of the beliefs vary, especially between the Latin Church, the Eastern Catholic Churches of Greek tradition, and the other Eastern Catholic Churches. Liturgical and canonical practices vary between all these particular Churches constituting the Roman Catholic Church.
In the understanding of another Church that identifies Catholicism with itself, such as the Eastern Orthodox and Oriental Orthodox Churches, clear identification of certain beliefs may sometimes be more difficult, because of the lack of a central authority like that of the Roman Catholic Church. On the other hand, practices are more uniform, as indicated, for instance, in the single liturgical rite employed, in various languages, within the Eastern Orthodox Church, in contrast to the variety of liturgical rites in the Roman Catholic Church.
In all these cases the beliefs and practices of Catholicism would be identical with the beliefs and practices of the Church in question. If Catholicism is extended to cover all who consider themselves spiritual descendants of the Apostles, a search for beliefs and practices that distinguish it from other forms of Christianity would be meaningless. Only if Catholicism is understood in the sense given to the word by those who use it to distinguish their position from a Calvinistic or Puritan form of Protestantism is it meaningful to attempt to draw up a list of common characteristic beliefs and practices of Catholicism. In this interpretation, evidently by no means shared by all, Catholicism includes the Roman Catholic Church, the various Churches of Eastern Christianity, the Old Catholic Church, Anglicanism, and at least some of the "independent Catholic Churches".
The beliefs and practices of Catholicism, as thus understood, include:
See main article: Catholic sacraments.
See main article: Sacred Mysteries.
See main article: Anglican sacraments. Churches in the Catholic tradition administer seven sacraments or "sacred mysteries": Baptism, Confirmation or Chrismation, Eucharist, Penance, Anointing of the Sick, Holy Orders, and Matrimony." In some Catholic churches this number is regarded as a convention only.
In Catholicism, a sacrament is considered to be an efficacious visible sign of God's invisible grace. While the word mystery is used not only of these rites, but also with other meanings with reference to revelations of and about God and to God's mystical interaction with creation, the word sacrament (Latin: a solemn pledge), the usual term in the West, refers specifically to these rites.