anger, where does it come from and what does it bring?

When people act without controlling their feelings, there are cases where everything ends up getting worse.
Speaking of anger, most of the time it doesn't bring any happiness to anyone.

But getting the emotion of anger is a natural thing for a human being. So to move things to the happy side, we will need to control it. How?

The key here would be to understand what is behind the anger. There is always a reason there because anger is a secondary emotion, thus it arises after the primary emotion. Then why does it change to anger?
It may rely on your mood or physical condition. It also comes from the gap between your expectations and the actions taken by other parties. And sometimes you have a way of thinking about how things should be handled, but actually not everyone thinks or moves the same way.

So by knowing the root of it, you will be able to see if whether it can be changed by taking action from your side. If it can't, then just leave it and forget about it! If it can, then question the situation in a future-oriented way. It might make life just a little more easier.
Cheers!