Anger is a natural emotion, neither good nor bad. Its motivation and the way you manage it makes a difference in the way you feel, and the way others feel about you.
The Dalai Lama spoke of the difference between anger motivated by concern for another's well-being, for example the angry response when a child is about to do something dangerous, and anger that motivates hatred, as when anger is directed at another person who has done you some harm. In the first case, the anger is at the action and it dissipates once the action has been stopped. In the other, the anger is at the person and may lead to harmful action or negative feelings long after the action is over.