What are the two major divisions of the Islamic religion?

Islam, like many major world religions, encompasses diverse interpretations and practices, leading to distinct branches within the faith. The most significant and widely recognized of these divisions are Sunni and Shiite Islam. This fundamental split originated from a historical disagreement over who should succeed the Prophet Muhammad as the leader of the Muslim community after his death in 632 CE. This question of leadership, authority, and succession laid the groundwork for the theological and juridical differences that developed over centuries.

The majority of Muslims worldwide, approximately 85-90%, identify as Sunni. Sunnis believe that the Prophet Muhammad did not explicitly designate a successor, and therefore, the leader (Caliph) should be chosen by community consensus, based on their knowledge of his life and works. They accepted Abu Bakr, a close companion of the Prophet, as the first Caliph. Sunni Islam emphasizes following the "Sunnah," or the traditions and practices of the Prophet, as recorded in various hadith collections.

Conversely, Shiite Muslims, who constitute 10-13% of the global Muslim population, hold that leadership should have remained within the Prophet Muhammad's family. They believe that the Prophet divinely designated his cousin and son-in-law, Ali ibn Abi Talib, as his rightful successor and the first Imam. Shiites place special reverence on Ali and a line of Imams descended from him, viewing them as divinely guided spiritual leaders who possess special religious knowledge. This difference in the concept of religious authority and succession remains the core distinction between these two major branches of Islam.