There are two different types of muslims
Shia Islam
Shi’a is the short form of the historic phrase Shīʻatu ʻAlī(شيعة علي) meaning “followers”, “faction” or “party” of Muhammad‘s son-in-law and cousin Ali, whom the Shia believe to be Muhammad’s successor in the Caliphate. Twelver Shia (Ithnā’ashariyyah) is the largest branch of Shia Islam and the term Shia Muslim is often taken to refer to Twelvers by default. Shia Muslims constitute 10-20% of the world’s Muslim population and 38% of the Middle East‘s entire population
Shia Islam is divided into 3 main sectors or groups.
Twelvers:
Twelver Shī’ite or Imamiyyah (Imami Shi’a Islam) (Arabic: اثنا عشرية, Athnā‘ashariyyah orIthnā‘ashariyyah; Persian: شیعه دوازدهامامی, pronounced [ʃiːʔe-je dævɑzdæh emɑmiː]) is the largest branch of Shī’ī (Shi’a)Islam. Adherents of Twelver Shī’ism are commonly referred to as Twelvers, which is derived from their belief in twelve divinely ordained leaders, known as the Twelve Imāms, and their belief that the Mahdi will be the returned Twelfth Imamwho disappeared and is believed by Twelvers to be in occultation.
Sunni Islam
The word “Sunni” is believed to come from the term Sunnah (Arabic: سنة), which refers to the sayings and actions of the Islamic prophet Muhammad as recorded in hadiths
The Sunni branch of Islam stipulates that as a head of state, a caliph should be elected by Muslims or their representatives.
Followers of Shia Islam, however, believe a caliph should be an Imam chosen by God (Allah) from theAhl al-Bayt (the “Family of the House”, Muhammad’s direct descendents). From the end of the Rashidun period until 1924, caliphates, sometimes two at a single time, real and illusory, were ruled by dynasties. The first of these was theUmayyad dynasty, followed by the several other sometimes competing claimants and finally the Ottoman dynasty.