The government of democracy is something so complex and intricate that many facts can be generated. Three specific facts could relate to its origins and purpose.
Fact 1: "Democracy was first developed as a system of rule in Athens in the sixth century BC."
The Greek roots of democracy are essential. "Demos" meaning "people" help to establish how democracy is defined as a rule of the people. It did not apply to all people of Athens, though. All citizens could vote, but citizenship was something that the Athenians conferred upon with conditions. Yet, in stressing the idea that all citizens could vote, the Athenians receive the credit for the first democracy to be enacted.
Fact 2: Democracy has changed over time.
The Greek conception of "direct democracy" has been changed over time to be one in which democracy means voting for elected representatives. This notion of "representative democracy" is what most of the world governments that are democratic embraces.
Fact 3: Individual rights is an essential part of democracy.
With its emphasis on the rule and voice of the people, individual rights such as freedom of speech and freedom of the press are essential in order for democracy to flourish and remain a government "of the people, for the people, and by the people."
There are many more facts about democracy. These three are only a starting point in that process.