Democracy is a system of government based on the principle that the state's power is vested in the people and may be used by the people or their elected officials under a system of free elections. In theory, democracies may be either direct or representative.
A democracy has four major pillars consisting of a law, the safeguard of human rights, participation of the citizens and fair elections to choose and replace the body of government.
In a direct democracy, any an all citizens may act directly to enact public policy without the intermediary step of an elected official. In practice, this is only practical when applied to smaller groups of people. A working group, for example, may be based on this type of direct democracy.
In a representative democracy, the will of the people is to be enacted by elected officials. Free elections, the involvement of the public in all aspects of civic life, upholding human rights and the equal application of law to all citizens are cornerstones of democratic societies.
Democracy, being based on elections, is based on the notion of majority rules. What the majority of citizens vote for should be enacted. Majority rules, however, should never mean that the minority is oppressed and so most democratic states also have a constitution which enshrines the rights of all citizens, including minorities. These are called constitutional democracies, and include most of the democratic countries in the modern world.
A presidential democracy is a type of government where a president is elected by the people in a free election and gains power over the state and government, effectively gaining the majority of executive powers.
A constitutional democracy binds elected representatives to a constitution constraining the powers of officials.
A hybrid democracy uses parts of representative and direct democracies to form participatory democracies. Examples include the U.S. states of California, Vermont, the New England region and the country of Switzerland. The first democracy was a direct democracy performed by the Greek people.