Final answer:
A monarchy is a system of government led by a single individual, a monarch, who usually inherits the position and rules until death or abdication. Monarchies can be absolute or constitutional, with the latter being more common today, limiting the monarch's power through law or a constitution.
Step-by-step explanation:
A monarchy is a form of government in which the head of state is an individual, usually a monarch, who typically holds the position for life or until abdication. The term "monarch" refers to various titles such as king, queen, prince, and princess. The route to becoming a monarch is often through hereditary succession or a belief in some form of divine appointment or calling. In many countries, the role of a monarch is largely ceremonial, serving as a tradition or figurehead. However, in an absolute monarchy, the monarch has complete and unmitigated power over the state.
Contrarily, constitutional monarchies are systems where the monarch acts under the constraints of a constitution, whether unwritten, as in the United Kingdom, or written, as in Thailand. Despite being hereditary in many systems, some monarchies still exist where the position is elective, such as in the case of The Pope.
Today, there is a myriad of approaches to royal power, with some nations still maintaining powerful monarchs while others maintain those roles as symbolic gestures tied to the country's historical and cultural heritage.