There are many characteristics that democracies usually share.
The most important one of these is that citizens are allowed to participate in politics and chose their own leaders. In most cases, this is done through the process of voting during an election.
Another characteristic of democracies is that people are considered equal, and no one is considered to be above the law. This means that all people are required to follow the laws outlined in the Constitution. Finally, most democracies share a set of basic individual rights, such as freedom of speech and freedom of religion.