One of the three monotheistic world religions, Islam (Arabic for "submission") was founded in 7th-century Arabia by the Prophet Muhammad. Today, of the approximately 1 billion Muslims worldwide, less than one-fifth are Arab.
The community of all adherents of Islam is known as the ummah (nation), a term that embraces the sense of one Muslim people, overriding national and cultural boundaries.
At the core of Islam is the Koran, believed to be the word of Allah (Arabic for God) as revealed to Muhammad. Central to Muslim life are "the five pillars": The affirmation that "there is no god but God, and Muhammad is the messenger of God," five daily prayers, giving alms, dawn-to-dusk fasting during the month of Ramadan, and the pilgrimage to Mecca.
The sources of Islamic doctrine are the Koran, the Hadith and Sunnah (the traditions and practices of the prophet), consensus (by leading Islamic scholars about issues on which the Koran, Hadith, and Sunna offer no guidance), and inference by analogy (when judges and scholars devise a solution based on precedent, again because there is no historical ruling).
Sharia (Islamic law) embraces all aspects of Muslim life - public and private, devotional and secular, civil and criminal - and was compiled by scholars and jurists during the first three centuries of Islam.
After the prophet's death, Islam split into two major divisions over who should succeed as leader of the Muslim community. Sunni Islam followed a line of caliphs, starting with Abu Bakr, and Shiite Islam followed a hereditary line through Muhammad's son-in-law, Ali.
Sunni - The largest division encompassing 90 percent of all Muslims, Sunni Islam includes wide-ranging strands of interpretation, including the puritanical Wahhabis and the mystic Sufis.
Sunni Islam has four legal schools of thought - Hanafi, Maliki, Shafii, and Hanbali - which offer varying interpreta-tions of the canon law. The last, Hanbali, is the most conservative and rejects all sources of Islamic law except the Koran and the Hadith and Sunnah. It is the official school of Saudi Arabia and Qatar.
Wahhabi - Sunni puritanical movement founded by Muhammad ibn Abd al-Wahhab (c. 1703-1791). Wahhabism rejects all religious practices adopted after the 3rd century of the Muslim era (after c. 950).
The histories of Wahhabism and of the Saud tribe - the ruling family of Saudi Arabia - have been closely linked since the foundation of the movement. Ibn Abd al-Wahhab, who considered it his religious duty to conquer all other forms of Islam, was unwelcome among Arabian tribes - except the Sauds. They formed a pact with him in 1744 and began their conquest of Arabia 20 years later.
Wahhabism remains the dominant sect in Saudi Arabia, which has spread its influence to other Muslim countries through financial support for religious education.
Shiite - From the Arabic shiat Ali, the party of Ali, Shiite Islam is the second largest sect, making up about 10 percent of all Muslims. The Shiite branch originated in the strife of succession following the Prophet Muhammad's death. Shiism began as a political movement supporting the claims of Ali, cousin and son-in-law of Muhammad, to succeed the prophet as leader of the Muslim community.
Shiites are a minority in all Muslim countries except Azerbaijan and Iran, where Shiism was adopted as the state religion in the 16th century.
Sufi - A mystical movement developed in the 8th century in reaction to the perceived formalism and legalism of conventional Islam. (Some Muslims, such as Wahhabis, do not consider Sufis true Muslims.) The Sufis practiced a form of hermitic mysticism by withdrawing from the world and seeking a personal relationship and direct communication with God. Sufism, which developed religious orders and spread throughout the Muslim world, became a significant movement and vehicle for teaching Islam. The poet Rumi was a Sufi.
Ayatollah In Shiite Islam, the most learned of religious teachers and interpreters of the law.
Fatwa A legal opinion or decision by a religious leader on a matter of religious law.
Imam A leader of prayer in a mosque.
Jihad The terms means "struggle in the path of God," but has been commonly co-opted by Islamist groups to mean armed struggle or holy war against infidels.
Mujahideen Holy warriors or ones who carry out a jihad.
Mullah A Muslim teacher or interpreter of Islamic law.
Sharia Islamic law (literally, the road to the water hole).
Sheikh A learned Muslim.
Talib A student.
Ulema A council of Muslim scholars.