Answer: What makes the authority legitimate.
Explanation: An authority is defined by it's legitimacy. Based on legitimacy, authority is varied into three types, each highlighting what makes it legitimate or an accepted power within a community according to Max Weber. They include;
Legal-rational authority usually employed in modern society and derives it's legitimacy from written laws and constitution of a community or society.
Traditional authority usually adopted by monarch derives it's legitimacy from long standing cultural belief, Values and inclination.
Charismatic authority, inductive attractiveness and character seen in an individual.