This seems to be a good description of the different sects within Islam even though the site where I found it is about atheism.
atheism.about.com/library/FAQs/islam/blfaq_islam_sects.htm
Islam does not have nearly as many sects and divisions as does Christianity, but there are a few and it is worth knowing something about them. The two biggest are the Sunnis and the Shi’ites, with the Sunnis being the largest of all and representing the vast majority of Muslims. Shi’ites are a minority everywhere except Iran.
After them, the two most influential sects are the Sufis and the Wahhabis. The Sufis represent a mystical tradition in Islam, whereas the Wahhabis are a strict traditionalist tradition which is dominant on the Arabian peninsula, but has little support elsewhere.
Unlike churches, mosques are not denominational. Despite the differences among Muslims, traditional Friday prayer services are largely similar and Muslims of any background are welcome to attend services at any mosque.
Who are the Sunnis?
Sunnis are Muslims who are considered the more “orthodox” believers. Sunnis follow all of the most traditional beliefs and actions.
Who are the Shi’ites?
The term Shi’a is a shortened form of Shi’at Ali, which means “the party of Ali” - and at the time of Ali’s death in 661, that is probably all it was: a party or tendency of people who supported Ali’s claims to the caliphate. Over time, they became the largest non-Sunni sect in Islam.
Who are the Sufis?
Sufism is important to the development of Islam because it is in this tradition that the more spiritual and mystical aspects were preserved. This stands in contrast to the mainstream of Islam which, through its first centuries, was more concerned with the expansion and organization of the general community.
Who are the Kahrijites?
In Arabic, their label means “to go out” - they were, in effect, the first Mulism dissidents and rebels, being present almost from the dawn of Islam. Like later dissidents, they chose to separate themselves from the main body of believers, feeling that the majority of Muslims had lost the “true path.”
Who are the Wahhabis?
Muhammad ibn Abd al-Wahhab could be considered the first modern Islamic fundamentalist. He made the central point of his reform movement the idea that absolutely every idea added to Islam after the third century of the Mulsim era was false and should be eliminated.
Who are the Ismailis?
An early Shi’a sect which split from the main group because of a dispute over who should be considered the next Imam.
Who are the Zaidis?
Formed by Zaid, a grandson of Husain, the Zaidis have believed that the true Imam must publicly assert his claim to the title and seek to overthrow the corrupt regime run by unacceptable rulers.
Who are the Fatimids?
The Fatimids are a successor movement to the Isma’ilis and are descendants of Fatima and Ali through the line of Isma’il. In the tenth century, those descendants asserted themselves as caliphs in North Africa, and ruled Egypt from 969 to 1171.
Who are the Nizari?
This sect is actually very well known around the world, but under a different name: the Assassins.
Who are the Alawis?
Also known as Nusayris, the Alawis are a branch of Isma’ilism which has gone so far along its own path that many Muslims no longer even regard it as a form of Islam. The term Alawis actually just means “followers of Ali,” which is used in some countries to refer to all Shi’a in general. Some think that they worship Ali as God, but that isn’t entirely accurate.
Who are the Druze?
The Druze comprise another sect which is not widely regarded as being “truly” Muslim. This group diverged from mainstream Islam in the eleventh century when some Isma’ilis started to believe that God became manifest in the personality of a prophet or imam.
Who are the Baha’i?
Baha’i is another movement which is descended from Islam, but which most Muslims today no longer regard as authentically Islamic.
