Khalifah is a name or title which means "successor", "deputy" or "steward". It most commonly refers to the leader of a Caliphate, but is also used as a title among various Islamic religious groups and orders. Khalifa is sometimes also pronounced as "kalifa". There were 4 khalifas after Mohammed died, beginning with Abu Bakr. This was a difficult decision for the people to make, for no one except Mohammed had ever thought with foresight about who would rule after he would die. The Khilaafat (or Caliphate) was then contested and gave rise to the eventual division of the Islamic Umma into two groups, the Sunni and the Shi'a who interpret the word, Khalifa in differently nuanced ways.