A Christian denomination is a distinct religious body within Christianity, identified by traits such as a name, organisation, leadership and doctrine. Individual bodies, however, may use alternative terms to describe themselves, such as church or sometimes fellowship. Divisions between one group and another are defined by authority and doctrine; issues such as the nature of Jesus, the authority of apostolic succession, eschatology, and papal primacy may separate one denomination from another. Groups of denominations—often sharing broadly similar beliefs, practices, and historical ties—are sometimes known as "branches of Christianity" or "denominational families".
Some groups included on this list do not consider themselves denominations. For example, the Catholic Church considers itself the one true church and the Apostolic see, and as pre-denominational. The Orthodox Church also considers itself the original Church, and pre-denominational.
Other groups that are viewed by non-adherents as denominational are highly decentralized and do not have any formal denominational structure, authority, or record-keeping beyond the local congregation; several groups within Restoration Movement fall into this category.
Some groups are large (e.g. Catholics, Orthodox, Lutherans, Anglicans or Baptists), while others are just a few small churches, and in most cases the relative size is not evident in this list. Modern movements such as Fundamentalist Christianity, Pietism, Evangelicalism, Pentecostalism and the Holiness movement sometimes cross denominational lines, or in some cases create new denominations out of two or more continuing groups (as is the case for many United and uniting churches, for example). Such subtleties and complexities are not clearly depicted here.