Government is a system of rules and laws that enforces order, establishes rights and duties and governs a nation. Governments have evolved over time to include a wide variety of functions and purposes, from national defense to social care. Governments can be a positive force in society, improving the lives of citizens and encouraging business activity. They can also have negative effects, however, such as limiting individual liberty or creating economic inequalities.

People need a government to protect them from each other and from outside threats. Without it, citizens would be constantly fearful of violence from warring bands and foreign foes. Governments can create military, police and fire departments to deal with these threats. They can build roads and buildings, and provide education and other public services. Governments also make laws and policies to regulate the economy, define property rights, ensure fair competition in the private sector, uphold equality, and redistribute income.

The biggest role of a government is the provision of goods and services that individuals cannot efficiently or cost-effectively produce on their own. These include things like national security, preventing disease and protecting the environment. Governments may collect taxes to generate the funds necessary to operate their desired services and to cover any debts they incur. Some governments also charge fees for their services or sell securities to raise funds.

Some governments have a more reactive approach to their functions and only act when problems emerge. This can cause structural issues to go unaddressed, which may then become more severe than if the government had addressed them in the first place. Examples of this include overfishing and global warming.

In addition to the provision of public goods and services, some governments have a moral or philosophical mission that shapes their actions. Governments that support ideals such as egalitarianism might increase taxes to fund programs that reduce socioeconomic inequalities, or they might restrict the freedom of the press in order to safeguard privacy. Governments can also be influenced by their cultural context, which can affect their values and the kinds of policies they adopt.

Governments are a complex and varied concept, and each nation has its own unique form of governance. Various factors can influence the nature of a government, including geography or climate, intellectual and philosophical influences, and historical circumstances. There are many different political systems in existence, ranging from democracies to totalitarian regimes and a wide range of hybrids. Historically, the most common forms of government have included monarchy, aristocracy, timocracy, oligarchy and tyranny.