Can some one explain the differences between Sunni, Shia and other divisions and what the issues are?
The basic difference between the Sunnis and Shi’ites stems from a disagreement over who should be the successor to Muhammad, aka the caliph. Sunnis believed any devout male Muslim would do, but the Shi’ites believed only a descendent of Muhammad was eligible. Specifically they had Ali, Muhammad’s cousin & son-in-law, in mind. His supporters were called the Shi’at Ali (Party of Ali). Each group had their followers—the Sunnis had much more—and they split, went their separate ways, and kill each other whenever they get the chance.
There are some minor differences in practice, for example Sunnis only pay 2% of their income to the poor, whereas Shi’ites pay 20%, and the Shi’a have some different holidays. But the main point of disagreement is over the caliph issue.
The caliphs were all Sunnis, but the Shi’a had their own leaders, called imams. The “missing” 12th imam is who most Shi’ites believe is the “Mahdi” who will come and kill all the infidels and save the world at the end of time. Some Shi’ites believe the Mahdi is a different imam, i.e. the fifth, the seventh...depends on who you ask.
Sunnis are less divided, and the largest non-mainstream sect of Sunni Islam is the Wahhabis, also called Salafis. The word comes from aslaaf, which means ancestors or predecessors, because it is their predecessors (i.e. Muhammad and his cohorts and the first few “rightly guided” caliphs) whom they revere. They want to go back in time to this sort of puritannical, uber-orthodox, unthreatened Islam. Most Sunni terrorist groups are Wahhabi.
All this infighting is over a 1400 year-old disagreement over who could fill a position that no longer exists. Sad, isn’t it.