The Qur'an is the final revelation from God to mankind, revealed to the Prophet Muhammad over 23 years. It is comprised of 114 chapters of varying lengths, divided into verses. Some chapters were revealed in Mecca focusing on beliefs like tawhid (the oneness of God), while others revealed in Medina provided legislative rulings. The Qur'an remains in its original Arabic language, containing the exact words revealed by God through the angel Gabriel, and is one of the fundamental sources of Islamic teachings.