In the Sunni conception, a caliph is the political head of state in a Muslim land. According to Sunnis, the first caliph in Islam was Abu Bakr who was elected by a majority vote of select Muslim leaders at that time. For Shi'ites, imams are spiritual leaders, first and foremost. They are said to be inspired by God and they must be from the descendants of the Prophet Muhammad. The first "imam" in Shi'a Islam was 'Ali, Muhammad's cousin. By comparison, 'Ali is known among Sunnis as the fourth "caliph" of Islam.
