Answer:
A monarch is the head of a state in which sovereignty does not belong strictly to the people, but to a small part of it, which is the royal house that governs the nation. Therefore, in this case the sovereign is not replaced after a certain period of time, but his mandate lasts for life.
At present, the power of most modern monarchs has been limited or almost disappeared, and the rulers in practice are members of civil society, with royalty being a representative figure but without political interference.