Government is the mechanism through which an organization enforces its policies. It consists of three distinct institutions—legislative, executive, and judiciary—that work together to determine policy. Governments around the world exist to accomplish collective goals such as economic prosperity, secure national borders, and the safety of citizens. Governments also provide benefits to their citizens, ranging from education and healthcare to infrastructure for transportation.

Governments are typically organized into branches with specific powers, functions, and duties. This distribution of power differs between governments, as does the number of branches and their responsibilities. Most nations have a constitution, which is the document that defines the modality of their government and the rules for its formation.

The most important function of any government is providing security and peace for its citizens. This is a task that requires resources and a centralized authority that can compel citizen cooperation and create the plans necessary for defense, attack, and war. In addition, a nation needs a central body that oversees and directs the activities of its local governments.

Because no one business can afford to build and maintain large armies or provide for the health and safety of its citizens, government is the only institution capable of performing this role. Its ability to tax and draw upon the entire country’s resources, as well as to compel citizen compliance, gives it the unique advantage over private organizations of protecting its citizens from outside threats.

Governments may be composed of many different entities, such as the President, Vice President, heads of executive departments, and Cabinet members. In a republic, the President is the head of state and head of government; he or she nominates and approves Cabinet members and other high-ranking officials. A constitutional republic enshrines the rule of law and protects citizens’ rights and freedoms. A democratic republic empowers the citizenry to make laws and select representatives through direct or indirect democracy.

The ancient Greek philosophers Plato and Aristotle theorized a great deal about the nature of government and its proper form. On the whole, they favored aristocracy-leadership by a small, elite ruling class that was thought to be morally and intellectually superior and best qualified to govern in the people’s interests.

As civilization expanded, monarchs increasingly shared the burden of governing with groups they could rely on for advice and assistance. In England this trend led to the development of Parliament, a legislative assembly that replaced the king or queen as the main source of day-to-day governmental power. Eventually, most European countries developed Parliament-style governments, as did many other countries.

The ideals of democracy include citizen participation and engagement, freedom and equality, limits on the power of the government, checks and balances, and accountability of officials. A key feature of democracy is that every eligible citizen has the right to vote in regular and free elections and that elected and appointed officials must be held accountable for their actions. A democratic government should encourage competing political parties to offer voters a range of options.