The document provides information about the religious pilgrimage known as the Hajj, which is one of the five pillars of Islam. It explains that during the Hajj, millions of Muslim pilgrims arrive in Mecca and perform a series of rituals over several days. These include circling the Kaaba seven times, running between the hills of Safa and Marwa, spending a day on Mount Arafat praying and asking for forgiveness, throwing stones at pillars in Mina, and shaving their hair or sacrificing an animal before returning to circle the Kaaba again. Upon completing the Hajj, pilgrims receive the title of Hajji, showing they have fulfilled this important religious duty in Islam.