The Koran, also known as the Quran, is the central religious text of Islam. It is composed of 114 chapters, or suras, which are believed to be the words of Allah revealed to the Prophet Muhammad. The Koran is divided into two parts: the Meccan suras, which were revealed in Mecca before the migration to Medina, and the Medinan suras, which were revealed after the migration. Each sura contains verses, or ayat, which are the basis of Islamic law and practice. The Koran is the most important source of guidance for Muslims, and it is recited and studied in mosques around the world.