Absolute Monarchy: This is a form of monarchy where the monarch holds supreme autocratic authority, principally not being restricted by written laws, legislature, or customs.
Constitutional Monarchy: It's a form of government in which a monarch acts as head of state within the parameters of a constitution (whether it be an uncodified or codified constitution).
Divine Right: This is the doctrine that kings and queens have a God-given right to rule and that rebellion against them is a sin.