Sunni Islam is the largest denomination of Islam. The word Sunni comes from the word Sunnah, which means following the words and actions or example of the Prophet Muhammad. Sunnis accept that the first four Caliphs (leaders of the Muslim communities worldwide), including Ali, were the rightful followers of Muhammad.
Sunni Muslims believe that Muhammad intended that the Muslim community choose a successor, or caliph, by consensus to lead the theocracy (earthly kingdom under divine rule) he had established.
The Quran, the Prophet's hadith, or sayings, and the sunna, or customs, are central to the belief system of Sunni Islam. So are the five pillars of Islam. Sunnis also believe in Islamic law.
Sunni Madh'habs – Theological Schools of Thought or Scholarship
The four prominent schools of Islamic thought (or Madh'habs) of Sunni Islam are each named by students of the classical jurist who taught them. The Sunni schools (and where they are commonly found) are:
Fiqh is an expansion of the Sharia Islamic law—based directly on the Quran and Sunnah—that complements Shariah by incorporating evolved rulings and interpretations of Islamic jurists. Fiqh deals with the observance of rituals, morals and social legislation. A person trained in fiqh is known as a Faqih (plural Fuqaha). These four schools share most of their rulings, but differ on the particular hadiths they accept as authentic and the weight they give to analogy or reason (qiyas) in deciding difficulties.