My friend ,I dont think this question will lead you to sucess in life . why to hurt people beliefs ? beg you to take in right spirt .... there are lot of exciting topics of the era to be discussed , why such religios topic when it is about to have a riot in the country . forgive me if i hurt you.

The division between Shia and Sunni dates back to the death of the Prophet Muhammad, and the question of who was to take over the leadership of the Muslim nation. Sunni Muslims agree with the position taken by many of the Prophet's companions, that the new leader should be elected from among those capable of the job. This is what was done, and the Prophet Muhammad's close friend and advisor, Abu Bakr, became the first Caliph of the Islamic nation. The word "Sunni" in Arabic comes from a word meaning "one who follows the traditions of the Prophet."

Muhammad sahab the Prophet of Islam was above this discrimination , sunni and shia discrimination came very later after His death when Muslims of those days divided in to two groups for Khilafat a group wanted to make Hajrat Ali, Son in Law of Muhammad sahab as Khalifa others accepted him as 3rd Khalifa, Later this discrimination led to Battle of Qarbala

Nhi malum,, par ab jaan gaya,, hun,, jawab pad kar..