Answer:
Constitutional monarchy (or limited monarchy) is a form of government in which a monarch acts as head of state within the parameters of a constitution, whether it is written or not.
This form of government differs from absolute monarchy in which an absolute monarch serves as the source of power in the state and is not legally bound by any constitution.
Most constitutional monarchies employ a parliamentary system in which the monarch may have strictly ceremonial duties or may have reserve powers, depending on the constitution.
Under most modern constitutional monarchies, such as the United Kingdom, there is also a prime minister who is the head of government and exercises effective political power.