There are approximately 1.2 billion Muslims worldwide, making up around 1/5 of the global population. While only 18% of Muslims live in the Arab world, the largest Muslim communities are found in Indonesia, Pakistan, Bangladesh, India, Turkey, Iran, Egypt, Nigeria, and China. The document outlines the key beliefs and practices of Islam, including the life of the prophet Muhammad, the five pillars of faith, and Islamic holy sites like Mecca and the Kaaba.