"Acceptance is a person's assent to the reality of a situation, recognizing a process or condition(often a negative or uncomfortable situation) without attempting to change it, protest, or exit."
Acceptance is very important to having a healthy self esteem. Having it be apart of your life means that you are not closed off emotionally and mentally. Different ways to go about it:
Accepting Who You Are: Knowing who you are and accepting, liking and loving it. This is the loving and being happy with yourself right now. It is like a contract with yourself to validate, appreciate, accept and support who you are at this point in time. It is like you being ok with your car right now. One day you will want a nicer newer/bigger car. But you see the car you have now and accept it for the positives.
Maybe it saves you money on gas or the insurance is really low. Seeing the positive in what you have and really appreciating it. It is not who you were in the past or who you will be in the future. It is validating who you are in the present moment. Everyone will and do change from who they are now. But there are advantages to who you are now and who you will become. It might seem to you that who you are now
Acceptance of Others: People waste so much time and energy on hatred and prejudice against other people. People believe that if you accept others that you will be affected by them. For example, if you don't agree with gay marriage, and you believe that by accepting it, your world will change as a result.
The opposite is actually true. By being prejudice and bias against a certain group of people you are actually allowing it to change your world. You spend countless hours worrying about it, being angry about it. Possibly protesting and writing angry letters. If you just accept what others do and know that everyone has a right to live how ever they want to live. That idea alone will set you free. Your mind will be more relaxed and open to concentrate on things that make you happy.
This way of thinking can be on a small day to day scale also. Try to learn to not be so bothered by people. Especially the ones you don't like. If someone does something that really gets on your nerves, try to let it go and accept them for who they are. They are doing what they think it is best for them at the moment. Always protect yourself of coarse. But if no harm is coming to you or your loved ones, just be okay with the people you encounter in life.
It will save you the tiem of being upset for hours thining about someone that probably isn't thinking about you.