Governments create the rules that citizens live by, protect them from outside interference, and provide for their well-being and happiness. Although the specifics differ from place to place, all governments share a common core of functions. They govern societies, foreign affairs, the economy, and public services. They also have the ability to tax and make laws that affect people in ways that are not regulated by other forms of law. In addition, they provide a means for citizens to participate in democracy, which involves voting and making their opinions known to those in power.

Government officials can be found at many levels — local, county, state and federal. Each level of government focuses on specific priorities and tasks, such as maintaining state colleges and universities, managing wildlife, constructing roads and bridges, and protecting the environment. They also allocate money for things that are of a national importance, such as defense and social security. Governments also have the responsibility to provide some goods and services to their citizens that are not able to be provided by private companies, such as a safe drinking water and free education. These are called public goods. Governments can protect these goods by levying taxes and tariffs, or by authorizing borrowing to cover costs. They may also direct spending, which is often done by referring bills that specify what the money will be spent on.

One of the most important jobs of government is keeping its citizens safe, whether by providing police forces, fire departments, and military service or by setting safety standards such as traffic signals, zoning laws, and sewage treatment plants. The government also regulates the activities of business, which helps to keep workers, consumers and animals safe from harmful substances such as lead, mercury, DDT and PCBs.

Governments are very diverse, with some resembling democracies and others resembling authoritarian models. A goal of political science is to create a classification of forms of government, or a typology. However, defining a form of government is challenging because many political systems have evolved from socio-economic movements, which have competing ideologies. In addition, the boundaries between different forms of government are not always clear. Nevertheless, the basic principles of each are: majoritarian decision making with minority rights, limited government with checks and balances, economic freedom and private ownership of property, equality, competition between political parties, and a Bill of Rights. For example, a democratic government will allow citizens to vote for their elected representatives and will limit the amount of power of the few. The U.S. Constitution, for instance, created a system of three branches of government that limits the power of any one branch to prevent abuses. The United States was not the first country to develop this system of government; it originated in antiquity, and was influenced by Aristotle’s “Politics.” The U.S. Constitution’s framers were also influenced by John Locke, who wrote in the 17th century that the key to a successful democracy was limiting the power of the executive and legislative branches.