World religions is a category used in the study of religion for the largest and most widespread religious movements. Christianity, Islam, Judaism, Hinduism, and Buddhism are always included in the list; they are known as the "Big Five". Some scholars also include other religions, such as Sikhism, Zoroastrianism, or the Bahá'í Faith. The term "world religions" is used to compare them with other groups, such as indigenous religions and new religious movements.