A democracy means rule by the people. The name is used for different forms of government, where the people can take part in the decisions that affect the way their community is run. There are two major types:

1. The people meet to decide about new laws, and changes to existing ones. This is usually called direct democracy. This is what Classical Athens had.
2. The people elect their leaders. These leaders take this decision about laws. This is commonly called representative democracy. The process of choosing is called election. Elections are either held periodically, or when an officeholder dies. This is the kind the United States has.

Edited from: https://simple.wikipedia.org/wiki/Democracy