The difference between Sunni and Shiite Muslims are predominately political and stem from disagreements after the death of Muhammed. Similar to the divisions of Protestants and Catholics within the Christian community, most elemental tenets of the faith remain agreed upon by both branches.
Sunni Muslims make up more than 85 percent of the world's Muslim population. While sharing the same articles of Muslim belief, both Sunni and Shiite do not consider themselves identified with a group and simply call themselves "Muslims" in spite of their differences.
Dating back to the death of the prophet Muhammed, when a disagreement arose as to who should take over the leadership in the Muslim nation. The Shiite Muslims believed the leadership should have been passed down to Muhammed's son-in-law. Historically Shiites have not recognized the authority of elected Muslim officials, instead choosing to follow imams, who they believe have been ordained by the Prophet Muhammed.
These imams are said to be sinless and infallible by the Shiites, who enshrine these men and perform pilgrimages to their tombs in hopes of divine intercession. Sunni Muslims counter that leadership is not by birthright, but by earning the people's trust, with no intercession of saints or deifying of imams.