What is Islam?:
The name of the religion is Islam, which comes from an Arabic root word meaning "peace" and "submission." Islam teaches that one can only find peace in one's life by submitting to Almighty God (Allah) in heart, soul and deed. The same Arabic root word gives us "Salaam alaykum," ("Peace be with you"), the universal Muslim greeting.

At heart, Sunnis and Shiites are like Catholics and Protestants in the commonality of some fundamental beliefs. But their differences, especially in nations where the Sunni-Shiite split is exacerbated by each other's proximity (as in Iraq and Lebanon), run so deep that intolerance and violence shadow the two groups, making coexistence difficult.


Islam's Origins
In 610 A.D., Muhammad ibn Abdallah was a successful 40-year-old Arab businessman and tradesman. Every year he retired to a cave near Mecca, in present-day Saudi Arabia, to pray and fast. Beginning that year on his cave retreats, he had overpowering revelation of the word of God, what would later come to be known as the Quran (which means recitation). By 610, Muhammad was preaching the Quran and directing his earliest followers to build a community, or ummah, where the practical and the compassionate (rather than the theological) was to predominate.

The year 622 marks the founding of Islam as a religion: It was the year of the hijrah, or migration, by Muhammad and his followers. They founded the first truly Islamic ummah in Medina.

By the time of Muhammad's death in 632, Islam had conquered the Arabian peninsula roughly up to what today would be Saudi Arabia's borders with Jordan and Iraq. Within a century, Islam would spread to western India, the Caucasus, Turkey, North Africa and the Iberian Peninsula. Its furthest advance was to the heart of present-day France, where the armies of Charles Martel stopped the conquerors in 732 in the Battles of Tours and Poitiers.

The Prophet Muhammad's Succession
At Muhammad's death in 632, Abu Bakr, a close companion of the Prophet, became his successor, or caliph. Most Muslims agreed that the most able and pious of the Prophet's followers should be his caliphs. Their followers would come to be known as the orthodox branch of Islam, or Sunnis.

A few Muslims disagreed, arguing for a line of succession based on bloodlines. To those dissenters, the succession should have immediately gone to Ali, the fourth caliph -- who took the helm after some of his followers assassinated Caliph Uthman, his predecessor. Followers of Ali would eventually form Shiite Islam.

What Sunnis and Shiites Believe
The Quran, the Prophet's hadith, or sayings, and the sunna, or customs, are central to the belief system of both Sunnis and Shiites. So are the five pillars of Islam: The recitation of the creed ("There is no God but God, and Muhammad is his Prophet"); the salat, or the recitation of prayers five times a day; zakat, or the obligatory giving of alms to the poor according to one's means; fasting from sunup to sunset during the month of Ramadan; and the hajj, or pilgrimage, to Mecca at least once in a Muslim's lifetime, means permitting. The Quran does call for "jihad" as a military struggle on behalf of Islam. But the Quran also refers to jihad as an internal, individual, spiritual struggle toward self-improvement, moral cleansing and intellectual effort. It is said that Prophet Muhammad considered the armed-struggle version of holy war "the little jihad," but considered the spiritual, individual version of holy war--the war within oneself--as "the great jihad."

Including the "jihad" as one of the five pillars of Islam is a common Western misunderstanding. Jihad is not among the five basic pillars of Islam. Still, "jihad" is considered to be every Muslim's duty--be it the struggle to improve society, preventing the exploitation of the poor or vulnerable, or improving oneself before the Day of Judgment.

Sunnis and Shiites also believe in Islamic law. But its application varies.

Several militant or political Islamic organizations have adopted the term in their monikers. These include Egypt's Jamaat al-Jihad community, established in the late 1970s by militant Sunnis and responsible for the assassination of Egyptian President Anwar Sadat in 1981; Islamic Jihad, an offshoot of Hezbollah in Lebanon and used since 1982 in covert military activities; and Palestinian Islamic Jihad, which has conducted suicide attacks on Israeli targets. All three groups are on the U.S. State Department's list of Foreign Terrorist Organizations.

Jihad is the Arabic for what can be variously translated as "struggle" or "effort," or "to strive," "to exert," "to fight," depending on the context. In the West, the word is generally understood to mean "holy war," and the terms are given, inaccurately, exclusively military connotations.

Where Sunnis and Shiites Differ
Sunnis accept that the first four Caliphs, including Ali, were the rightful followers of Muhammad. However--rather like Protestantism in Christianity--they don't grant the kind of divinely inspired status to their clerics that Shiites do with their imams. Shiites believe imams are descendants of the Prophet.

Islam has no codified laws per se. It has various schools of law. While Sunni doctrine is more rigidly aligned in accordance with those various schools, its hierarchical structure is looser and often falls under state, rather than clerical, control. The opposite is true in Shiitism: The doctrine is somewhat more open to interpretation but the clerical hierarchy is more defined and, as in Iran, the ultimate authority is the imam, not the state.

Both Sunnis and Shiites break down into various sects that range from puritanical (as with Sunni Wahhabism, prevalent in Saudi Arabia) to somewhat mysterious (as with the Druze of Lebanon, Syria and Israel, who form an offshoot of Shiitism).

Including the "jihad" as one of the five pillars of Islam is a common Western misunderstanding. Jihad is not among the five basic pillars of Islam. Still, "jihad" is considered to be every Muslim's duty--be it the struggle to improve society, preventing the exploitation of the poor or vulnerable, or improving oneself before the Day of Judgment.