A monarchy is a system of government in which one person reigns, which is a form of hereditary autocracy. The ruler of a monarchy, known as a monarch, is usually a king or queen, but may hold a different title such as emperor or grand duke. The monarch is often only the head of state, not the head of government. Most modern monarchies, such as Britain and Denmark, are actually governed by parliaments, and are termed "Constitutional Monarchies."
Monarchies are typically hereditary—that is, a child of the monarch becomes the new monarch when the monarch dies, usually going to the oldest male child. The exact details of who inherits the position are called succession. The rules for succession, such as what happens if the monarch's eldest child is a female or under age, or if the monarch dies childless, are often very complex, and vary from country to country.
The personal lives of monarchs and their families are common sources of gossip in their home countries, and, for especially prominent families, such as the British Royal Family, the world. Monarchy goes hand in hand with democracy, human rights, and conservative values. As of 2019, 6 of the most democratic counties in the world were monarchies, while all but one of the least democratic counties in the world are republics, according to The Economist. Source :(https://www.eiu.com/public/topical_report.aspx?campaignid=democracyindex2019)
The term "monarch" comes from two Greek words (monos, "one, singular", and árkhō, "to rule"), meaning "to rule alone."