Democracy is all about people having a say in how they are ruled. This happens through a voting system. In a proper democracy, people put themselves forward to be elected by the voters. Anyone can put themselves forward. If the candidates are put forward by a government alone, that is not a proper democracy.
Then each person has a chance to tell everyone else what they would do if they were elected. It might be how they would change their parish, borough, town or city, or it might be government. It could also be a school council.
When everyone has had their chance to speak and to be listened to without any interference, then people vote in secret. If they can't vote in secret it is not a democracy.
Democracies can produce some very weird people, but mostly they cause good and useful people to be elected.
The opposite is a dictatorship, where the people have no say.
The world's first democracy was founded in Athens in Ancient Greek times. The picture above show you the hill that was used for speeches. It is opposite to the hill with the Acropolis on.