Different forms of government systems include democracy, authoritarianism, and monarchy. In a democracy, power resides with the people, who exercise it through regular elections and representation. Authoritarian regimes concentrate power in a single leader or party, often limiting political freedoms and dissent. Monarchies can be absolute or constitutional, where a royal family may hold significant power or serve as ceremonial figures. Other systems include theocracy, where religious leaders govern, and oligarchy, where a small group holds power. Each government system has distinct characteristics, implications for citizen rights, and levels of accountability.