An Imam is a religious LEADER in the Islamic faith, typically leading prayers and providing spiritual guidance. An EMIR is a ruler or prince of a region, usually with a high degree of autonomy. Omar was a companion of the Prophet Muhammad and one of the most influential figures in early Islamic history. Ameer is an Arabic title meaning 'COMMANDER' or 'LEADER'. A CALIPH is a successor to the Prophet Muhammad and the LEADER of the Muslim community.