A caliph is a chief civil and religious ruler in the Muslim community believed to be the successor of the Prophet Muhammad. Muslims or their representatives elect a caliph. Ottoman sultans claimed and held the caliph title until it was abolished in 1924.
After the death of the Prophet Muhammad, a disagreement occurred between Shi'a and Sunni Muslims over who should be the caliph. The Shi'a Muslims believed a caliph should be an Imam chosen by God from direct descendants of Prophet Muhammad. The Sunni Muslims believed a caliph should be elected or chosen by community consensus. In addition, they believed the caliph is a temporal political ruler, appointed to rule as the head of the Muslim world.