Here are the key terms.
Caliph: the civil and religious ruler of a Muslim state.
Council: an assembly called to pick the next Muslim caliph.
Shiite: a member of the branch of Islam that supports the descendants of Muhammad as his rightful succesors.
Sunni: the branch of Islam that follows orthodox tradition and accepts the validity of the first four caliphs elected as succesors to Muhammad. They believe in leading in the example of Muhammad.