Forgiveness is an abstract concept for some people, but the essence of forgiveness lies in letting go of your angry feelings towards another person for the wrong they have done you. Forgiveness is necessary in healing – more for you, than the person who has wronged you.
Forgiveness is actually a decision – something that you decide to do even if your emotions are still raging. You decide to strip the person/event of the power of hurting you. Forgiveness is not a one-time thing, though. Once you’ve made the decision to forgive, you will still need to deal with emotions for a while, but that decision is the big step forward.