Democracy is a universal value based on the freely spoken and expressed will of people to determine their own political, economic, social and cultural systems in all aspects of their lives.
Evolved over centuries, democracies share many common features but cannot be reduced to a single model.
In short, democracy pertains to the idea that everyone has the right to have their own beliefs, and to say and write what they think.
Every year on the 15th September, the United Nations celebrate these ideas on the International Day of Democracy.
The theme for International Democracy Day 2018 has not yet been annoucned.
Here is the link to the UN Democracy Day website.