Self-esteem is about how we perceive ourselves. It is usually based on decisions we have made about ourselves. Those decisions could be in response to our childhood experiences, but it can also be related to our general life experience. When we have low self-esteem, it might stop us from living our life fully or reaching our full potential.
Therapy can help us to become aware of our beliefs about ourselves and perhaps make connections between past relational dynamics and who we are now. This awareness, combined with curiosity and compassion, may then give us the opportunity to 'unlearn' what we tell ourselves (about ourselves, others and life) and make different choices.