This is a bit of a complex question. Democracy is allowing everyone in the group to have a say in what is going to happen for society as a whole. Such as those living in a city get to vote and choose what happens within their city.
The only problem is that it doesn't stop a mass of stupid people from voting for bad policies and destroying their community.
Topics are voted on and whatever the majority favors, is the direction EVERYONE has to take. From observation, it is pretty easy to spot in history when tons of people, thinking they are doing the right thing, ignore the facts of reality and end up destroying themselves. Sheep are easier to persuade and coax into making decisions that benefit others. Those that think for themselves are a lot less likely to jump on a bandwagon just because it is popular at the time. Those swept away by emotions tend to ruin things for others.
Now we HAVE democracy in the United States but we are NOT a democracy. We are a Constitutional Republic, meaning that our final law is the Constitution that was founded by our country's forefathers. This means that no matter where you are in the rankings of the system, you are subject to the limitations of power as listed in our Constitution. This is to help protect the rights of all citizens.
Did you think that we were a democracy? Where can you pinpoint in the world where democracy has worked perfectly and is still going strong?