Sacred book
The Koran is the sacred book of the world's second largest religion - Islam. Islam has around 1 billion followers. Only Christianity has more. Christianity has nearly 2 billion followers. Followers of Islam are called Muslims.
Also spelt 'Qur'an', the word means 'recitation'. A recitation is when somebody speaks - recites - out aloud lessons they have learned by heart. The Prophet Muhammad recited the Koran to his followers, who wrote it down.
The lessons are said to have been given to him by an angel. The angel was delivering messages from God. Muslims call God Allah.
From words to the page
When the Prophet Muhammad died in 632, experts think the Koran had not been written down. By 650, 18 years later, it probably had been. Experts agree it was probably the standard edition we have today. It has 114 chapters.