Originally Posted by PRISONERofJOY12
Islam only had one major schism which happened very early on in Islam's history.
The mainstream, and largest group is called Sunni.
The second group, (around 20% of muslims globally) are called Shia's. Found mainly in Iran.
The split is partly political, partly theological. It is very hard to summise as it requires a large amount of background knowledge of Islamic history and also, the differences, though at the root political and theological, are quite a long list.
Within Sunni Islam, it is 'possible' to argue thers another sect, called Sufi's, known as Islamic mystics (found mainly in Turkey). The Sufi's dont really follow different beliefs than any other Sunnis, they simply have a different way of doing things.
Those who are not familiar with Islam sometimes say Sunni Islam has four branches, known as madhabs. Madhab is a 'school of thought' and is simply different interpretation on what the Prophet meant in certain situations and what the Quran meant in certain ayah's etc... It is mainly to do with law and juriprudence. For example, the rules of divorce, inheritance, marriage. These are not sects however, as the beliefs are exactly the same. The differences are extremely tiny and lay in the nitty-gritty of the religion.
Hope that is clear.