Islamic schools and branches have different understandings of Islam. There are many different sects or denominations, schools of Islamic jurisprudence, and schools of Islamic theology, or ʿaqīdah (creed). Within Islamic groups themselves there may be differences, such as different orders (tariqa) within Sufism, and within Sunnī Islam different schools of theology (Atharī, Ashʿarī, Māturīdī) and jurisprudence (Ḥanafī, Mālikī, Shāfiʿī, Ḥanbalī). Groups in Islam may be numerous (the largest branches are Shīʿas and Sunnīs), or relatively small in size (Ibadis, Zaydīs, Ismāʿīlīs). Differences between the groups may not be well known to Muslims outside of scholarly circles, or may have induced enough passion to have resulted in political and religious violence (Barelvi, Deobandi, Salafism, Wahhabism). There are informal movements driven by ideas (such as Islamic modernism and Islamism) as well as organized groups with a governing body (Ahmadiyya, Ismāʿīlism, Nation of Islam). Some of the Islamic sects and groups regard certain others as deviant or accuse them of being not truly Muslim (for example, Sunnīs frequently discriminate Ahmadiyya, Alawites, Quranists, and Shīʿas). Some Islamic sects and groups date back to the early history of Islam between the 7th and 9th centuries CE (Kharijites, Sunnīs, Shīʿas), whereas others have arisen much more recently (Islamic neo-traditionalism, liberalism and progressivism, Islamic modernism, Salafism and Wahhabism) or even in the 20th century (Nation of Islam). Still others were influential in their time but are not longer in existence (non-Ibadi Kharijites, Muʿtazila, Murji'ah). Muslims who do not belong to, do not self-identify with, or cannot be readily classified under one of the identifiable Islamic schools and branches are known as non-denominational Muslims. Overview The original schism between Kharijites, Sunnīs, and Shīʿas among Muslims was disputed over the political and religious succession to the guidance of the Muslim community (Ummah) after the death of the Islamic prophet Muhammad. From their essentially political position, the Kharijites developed extreme doctrines that set them apart from both mainstream Sunnī and Shīʿa Muslims. Shīʿas believe ʿAlī ibn Abī Ṭālib is the true successor to Muhammad, while Sunnīs consider Abu Bakr to hold that position. The Kharijites broke away from both the Shīʿas and the Sunnīs during the First Fitna (the first Islamic Civil War); they were particularly noted for adopting a radical approach to takfīr (excommunication), whereby they declared both Sunnī and Shīʿa Muslims to be either infidels (kuffār) or false Muslims (munāfiḳūn), and therefore deemed them worthy of death for