A religious denomination is a subgroup within a religion that operates under a common name, tradition, and identity.
The term refers to the various Christian denominations (for example, Eastern Orthodox, Roman Catholic, and the many varieties of Protestantism). It is also used to describe the four branches of Judaism (Orthodox, Conservative, Reform, and Reconstructionist). Within Islam, it can refer to the branches or sects (such as Sunni, Shia, and Ahmadiyya), as well as their various subdivisions such as sub-sects,schools of jurisprudence,schools of theology and religious movements.
The world's largest religious denomination is Sunni Islam, followed by Roman Catholicism.
A Christian denomination is a generic term for a distinct religious body identified by traits such as a common name, structure, leadership and doctrine. Individual bodies, however, may use alternative terms to describe themselves, such as church or fellowship. Divisions between one group and another are defined by doctrine and church authority; issues such as the nature of Jesus, the authority of apostolic succession, eschatology, and papal primacy often separate one denomination from another. Groups of denominations often sharing broadly similar beliefs, practices, and historical ties are known as branches of Christianity.
Jewish religious movements, sometimes called "denominations" or "branches", include different groups which have developed among Jews from ancient times. Today, the main division is between the Orthodox, Reform, and Conservative lines, with several smaller movements alongside them. This threefold denominational structure is mainly present in the United States, while in Israel the fault lines are between the religious Orthodox and the non-religious.