Sunni Islam (i/) is the largest denomination of Islam. Its name comes from the word Sunnah, referring to the exemplary behaviour of the Islamic prophet Muhammad. The differences between Sunni and Shia Muslims arose from a disagreement over the choice of Muhammad's successor and subsequently acquired broader political significance, as well as theological and juridical dimensions.
According to Sunni traditions, Muhammad did not clearly designate a successor and the Muslim community acted according to his sunnah in electing his father-in-law Abu Bakr as the first caliph. This contrasts with the Shi'a view, which holds that Muhammad announced at the event of Ghadir Khumm his son-in-law and cousin Ali ibn Abi Talib as his successor. Unlike the first three caliphs, Ali was from the same clan as Muhammad, Banu Hashim, and Shia Muslims consider him legitimate, inter alia, by favour of his blood ties to Muhammad, too. Political tensions between Sunnis and Shias continued with varying intensity throughout Islamic history and they have been exacerbated in recent times by ethnic conflicts and the rise of Wahhabism.
As of 2009, Sunni Muslims constituted 87–90% of the world's Muslim population. Sunni Islam is the world's largest religious denomination, followed by Catholicism. Its adherents are referred to in Arabic as ahl as-sunnah wa l-jamāʻah ("the people of the sunnah and the community") or ahl as-sunnah for short. In English, its doctrines and practices are sometimes called Sunnism, while adherents are known as Sunni Muslims, Sunnis, Sunnites and Ahlus Sunnah. Sunni Islam is sometimes referred to as "orthodox Islam". However, other scholars of Islam, such as John Burton believe that there's no such thing as "orthodox Islam".
Sultan Salahuddin Abdul Aziz Mosque in Shah Alam, Selangor, Malaysia
Sunnī (Classical Arabic: سُنِّي/ˈsunniː/), also commonly referred to as Sunnīism, is a term derived from sunnah (سُنَّة/ˈsunna/, plural سُنَنsunan/ˈsunan/) meaning "habit", "usual practice", "custom", "tradition". The Muslim use of this term refers to the sayings and living habits of the prophet Muhammad. In Arabic, this branch of Islam is referred to as ahl as-sunnah wa l-jamāʻah (Arabic: أهل السنة والجماعة), "the people of the sunnah and the community", which is commonly shortened to ahl as-sunnah (Arabic أهل السنة).