Republic 共和政体 a country governed by elected representatives of the people, and led by a president, not a king or queen（如：the people's republic of china )

Democracy  民主政体
a system of government in which every citizen in the country can vote to elect its government officials （如：the united states)

Monarchy 君主政体

the system in which a country is ruled by a king or queen (如：the united kingdom）