Governments create the rules of a society, protect citizens from outside interference and threats, and provide goods, services, and jobs for their citizens. The role of governments varies from country to country, but they usually include the following essential components:
The legislative branch sets the laws of a country, the executive branch enforces those laws, and the judicial branch judges whether or not a law is fair. Historically, there have been many different forms of government, from monarchy to aristocracy to democracy, but the concept that a well-functioning government must divide power into these three distinct branches dates back to the Greek statesman and historian Polybius, who wrote about the Roman republic in the early centuries BC.
In addition to setting the laws of a nation, government must maintain strict security on the borders and within the country, ensuring that people can live peacefully together in harmony with nature. It must also ensure that the economy functions properly, providing a means for citizens to gain wealth and improve their quality of life.
The financial branch of government must collect taxes and loans to pay for the services it provides, ideally without undue influence from those it serves. It must also manage money to make sure that the money it spends is going to good use: for example, by building schools, paying for the police and fire department, and providing food, housing, and healthcare for the poor.
At the national level, government allocates funds for things such as social security, national defense, and management of federal parks. At the state and local level, representatives elected by the people seek funding for things that will help the people in their regions. For example, a county government may allocate money for a public college or university, maintenance of highways and bridges, and care for the elderly. Local governments may also fund things such as police and fire departments, mail delivery, and garbage collection.
One of the most important jobs of government is to provide common goods such as education, water, and wildlife that all people can use free of charge but which are in limited supply. Governments must ensure that a few people do not take more of these goods than is available, or they will disappear completely for everyone else.
At the same time, governments must be careful not to interfere with the free market by regulating too heavily in fields where the benefits of government intervention do not outweigh the costs. For instance, some governments regulate to protect against negative externalities, such as overfishing or global warming, but they must do so in a way that does not reduce the competitiveness of private businesses in those fields. This is a very delicate balance. Most governments, in fact, are more reactive than proactive, and they tend to wait until something goes wrong before taking action. This can lead to political turmoil and corruption.