Government is the set of rules and laws that adults make about how people should live together in a community. Government is also the institution that makes sure those rules are followed and judges any disputes about them. Government is necessary for the survival of any civilization.
Governments take many forms. They can be led by one person (autocracy), a group of people who come together in a specific way to form a group known as a political party (plural: parties), or the whole population (democracy). The most basic purpose of any government is to protect its citizens from harm and provide a stable environment in which economic development can occur. Governments are also responsible for providing essential services to their citizens such as police and fire departments, education, health care, public transportation, mail service, and food, housing, and medical care for those who cannot provide for themselves.
In the United States, our national, state, and local governments are elected by citizens to represent them in city councils, state legislatures, Congress, and other governing bodies. They draft laws to guide the people they serve and raise money through taxes on income, property, and sales. They then allocate funds to things they believe are important for their communities, such as education, maintenance of roads and bridges, police and fire departments, and wildlife management.
The framers of our Constitution outlined three different branches of government that are designed to limit the power of the President and other high-ranking officials and create checks and balances. The legislative branch, called Congress, writes laws, and those laws can only become law if they are passed by both chambers of the House and Senate. The executive branch, called the President, enforces these laws and makes decisions about how to spend federal funds. This includes making appointments to executive-level positions and negotiating with leaders of other countries. The judicial branch, called the Supreme Court and other courts, evaluates laws and determines if they are constitutional.
Modern political systems are classified as democracies, totalitarian regimes, and authoritarian regimes with a wide range of hybrid systems between these two. Governments are also categorized by the way they gain power, including democratic elections, hereditary succession, and other ways of choosing rulers.
In most western democracies, people elect leaders to government through an electoral process that ensures some level of minority representation and the right to vote. Governments are the largest employers around the world, and they have a variety of responsibilities that make them complex to run. This complexity is why the United States and other countries like it have a system of checks and balances that limits the powers of government officials and guarantees people their rights.