Self-esteem refers to how one views and thinks about themselves. It involves feelings of self-respect, self-worth, and self-value. High self-esteem involves having a good opinion of oneself, while low self-esteem involves having a poor opinion. One's self-esteem is developed throughout their life based on experiences, particularly childhood experiences, and is influenced by factors like praise, success, relationships, and treatment by others. Having healthy self-esteem is important as it promotes confidence, happiness, and positive relationships.