Self-esteem ( or self-worth ) describes how one regards themselves, independently of temporary situations, states, or things outside of their control.
Healthy self-esteem means that a person has a healthy sense of self-worth that is relatively unaffected by fleeting emotions, thoughts or situations. You can be confident in who you are without the need for approval from others, the need to feel "good", or the need to succeed in your goals.
For most people, this type of confidence is based on long-term psychological work done to create beliefs of worthiness, acceptance and integrity.
Self-esteem is not the same thing as self-confidence, however the two are connected.
It's an internalized perspective on oneself, which plays a significant role in;
A low self-esteem can have debilitating effects on a persons ability to live and enjoy their life.
An unusually high self-esteem can also be unhealthy, fostering a belief that one is superior to others, feelings of entitlement, unreasonable expectations, and even narcissitic behaviors.