Anger is a part of everyone's personality. People who say they "never get angry" are fooling themselves. Everyone gets angry. Anger is an emotion, not the action people take when they feel the emotion. Anger is to help one's self and others get clear on where the angry person is and how they're feeling (like they've been stepped on :-) It's not something "personal" or an attack of another, it's only about the person feeling the feeling, when expressed well, it is very helpful to both the person expressing and the person hearing. It's an opportunity to understand the angry person better and help them.

I think anger is very misunderstood, especially by clients who have never had it expressed by someone else in a helpful manner or who have been afraid to express their own. Like other feelings of those in therapy, what it is, how it feels, how to express it, etc. often has to be "taught" by the therapist's example.

I learned about anger when a boss got angry with me and I knew I was not the one causing his problems, his own misunderstanding was causing it. I kept stating my truth and eventually he heard me, apologized and both of us worked to solve his problem together.

If you do not understand why someone seems angry, ask them if they are angry (what sounds like anger to you might be something else to them and since they are the one emoting, you have to ask them what it is if you are not sure, if they don't say, "I am angry that you are doing X, Y, or Z") and if it is because of something you have done or not done. Anger is an urgent call for communication and help. It's a HEY THERE! I HAVE A PROBLEM AND I WANT YOUR HELP RESOLVING IT!