Islam means acceptance and submission to God and following his commands without the possibility of polytheism, the word Islam is a triliteral of the word salaam which translates to peace, and derived from the Arabic verb Aslam which means to submit or surrender, followers of Islam are called Muslims
Islam was founded by prophet Muhammad (Peace be upon him) when the first revelation of the Islamic faith known as the Qur'an was descended on him by the angel Gabriel (or Jibreel) while in a cave in Mecca during the ninth month of the Muslim calendar known as Ramadan and continued to do so for the next 23 years, all the revelations that the prophet received from Allah were compiled into what we see in the present day's Qur'an.
Many view Islam as the faith taught by the ancient Prophets, Abraham, David, Moses and Jesus (Peace be upon them) and Muhammad's (Pbuh) role as the last prophet was to formalize,clarify and purify the faith by removing any added errors.
Islam's development resulted in major political, economic, and military effects inside and outside of the Islamic world and within a century this empire had stretched from the Atlantic Ocean in the west to Central Asia in the east and the Islamic civilization was one of the most advanced in the world during the Middle Ages
Islam is divided into two groups, the Sunni Muslims who are the followers of the Hanifa schools and they constitute a majority of the Islamic faith. They follow three sources of law which are the Qur'an, Hadith and consensus of Muslims. The other group is the Shi'ite Muslims who are followers of the Jaafari school and they constitute a minority of the Islamic faith, they split from the Sunnis due to a dispute over the successor of prophet Muhammad (Pbuh), they believe in twelve Imams who are descendents of the prophet and await the appearance of the twelfth Imam the Mahdi to guide humans toward justice and peace.
Today Islam is one of the world's major religions, with followers estimated to be over 1 billion or about 23 percent of the world's population and that number is growing with each passing day.