It is generally said that self-esteem consists of two main types of things. On the one hand, there is the feeling that other people like and/or love us and that we are worthy of their affection and acceptance. On the other hand, there is our own feeling that we are competent and able to do things for ourselves. There are at least two ways in which these play a role in our lives.
First, self-esteem plays a role in our lives because we strive to achieve it. We want to feel good about ourselves. This is a major reason why we try to get others to like us and accept us. It is also a major reason why we try to become good at things. Self-esteem, then, is an important motivator for us in our lives.
Second, self-esteem does a great deal to determine our quality of life. If we have self-esteem, we are much likelier to be happy than if we do not have it. This means that we are much more likely to enjoy a good quality of life.
Self-esteem, then, is important in at least two major ways. It motivates us to work hard in our relationships and to become adept at various skills. It also is a major factor in determining the quality of life that we enjoy.